Need advice on bringing in the house 2 strays.

I stumbled upon this forum as i was looking for information and guides on how to help ease strays into a household, and from what i have seen/read i feel like i should ask my questions here(Big, long story time, i apologize.)
 
Me and my mother moved in with my stepdads mom a month ago to take care of her and i found out when we have a large number of stray cats. I got super excited because i love cats and where i lived before was in the middle of fields, not in the middle of a town. At first it was just one cat coming up because it was following my brother from down the road where they used to feed it, so i started putting food out. It never had a set time so i tried to make sure there was always a bit of food. We know it was let out when it was pretty small because my sister-in-law told me it was pretty small when she first started feeding it, i really doubt it is much older then a year. Eventually a few other cats would come around because of the buffet of cat food in the back yard.
 
Other strays i've had were raised from a kitten up, not full grown. One is a black and white one we call Oreo and the other is a black one we call Spook/Mr Kitty. I was reading a lot of the threads about bringing strays in and my experience seems to be a bit different, that's the main reason im posting.
 
Both cats are very affectionate with people, they will let us pick them up and move/hold them, and they tolerate each other. We have seen no fighting between them, they might not be cuddling up and sleeping together but they can be in the same areas and not care. We also have 2 dogs(one dog stays with stepdad most the time but comes up on weekends with him and the other is a maltipoo that stays in the house) Spook switches between running from the dogs and just jumping out of reach. Oreo on the other hand has no problem with the dogs and will play with them(the big dog keeps drooling on him).
 
I suspect Spook used to be someones pet because it is highly vocal with us and knows to sit at the door and meow. I also think he is a bit older then he looks. I KNOW that at the very least Oreo has been an outside, neighborhood cat for most of his life. These 2 just seem a bit special/different to me, compared to the numerous stray cats i have fed and watched over the years They don't run from most people and will always try and get into the house. Oreo has been getting faster with sneaking in and then he goes to the middle of the living room and flops. Spook will constantly intertwine with your legs and beg for attention.

I thought they were like this with everyone but over the past couple weeks we have heard from other people on our street that knows these cats, that they dine and dash. Oreo will always come and jump on my lap anytime i go outside and sit down, whether i call him or not. He will curl up and sleep on me and has even meowed at me some. Found out recently he doesn't do that with anyone else and so far i am the only one that he will allow to hold him for longer then a simple pick up and move thing. Spook has bonded with my grandmother who has Alzheimer and seems to actually be helping her. My mom keeps saying we have been adopted by these 2 cats, and we in turn want to fully adopt and bring them in.

I have no clue how to go about doing this. All the stuff i have read so far for bringing in strays seems to be only for ones that are skittish. We have let the cats in a few times with all the bedroom doors closed to see how they are and they just poke around, find the cat food in the kitchen, eat, play(Oreo), and beg for attention(Spook) Then we put them back outside because we have nothing prepared for extended inside times. I have a box outside with a fleece little blanket and towels for when it first started getting cold outside for Oreo and he sleeps there every night. Spook normally doesn't come here at night but that's changed recently, so we are getting another box for a bed.

I keep telling mom and grandma we cant let them in for long/full time until we get them to the vet and also that we need to get supplies first. So after all that background info here are my questions.-

--What all things do i need to get for these 2 adult cats to be let in?
--How do i deal/handle the litter box situation? Do i need a special kind to encourage its use or some kind of training thing? <--This is honestly my biggest concern(i have never brought in an adult stray cat so i will admit to completely ignorance of this) 
--Any recommended items or supplies that wont bankrupt me?
--Any advice on toys for cats that don't seem to play around much? I really don't want him to be bored or sad.

I'm currently sick with the Flu so i am really hoping this post was ok. I should be able to answer any questions someone asks about what i was trying to say. Really hope i did this right. And an advanced thank you if anyone is willing to try and help talk me through this.

Here are what the little cuties look like. I don't have a great one of Spook yet.

Thank you for wanting to help these two sweet strays.

Step one is to get them to the vet.  They need to be spayed/neutered if they have not been previously.  This is so very important for them both.  They will also need some blood tests and vaccines.  

I would start with a room of their own for a few days.  This can be your bedroom if needed, but you really want to be sure they are out in the open and not hiding under your bed or behind or under dressers.  If this becomes a problem then you will need to block those areas off.

Most cat instinctively learn to use a litter box very quickly.  The golden rule for litter boxes is one box per cat then one extra.  So you will need 3.  If space is a problem you will at least need two.  There is some special litter called Dr. Elsey's Litter Attract.  You can use it straight or just mix some in with the litter you choose.  It has special herbs that attract the cats to the box.  If the cats do have an accident sop it up with a paper towel and bury that in the litter.  That too will attract them.  Never punish them for having accidents.  It may take a few days.  Also get a good enzymatic cleaner if you need to clean up urine or feces.  The enzymes will break down the proteins so the animal will not want to go back to that spot.  I like to use litter mats under the litter box too.  

If you plan to make the cats inside cats you need to be diligent.  They may cry or yowl to go outside.  This will diminish with time.  Yet it will get worse and worse if the cats are not spayed//neutered.  Keeping them in one room for a few days helps them to acclimate to their new surroundings.  You can then slowly introduce them to the rest of the house.  It is important that others in the family be on board to help be sure the cats remain inside.

As far as toys, cats love simple toys.  Even just rolled up paper.  My cats love string or shoe laces.  There are tons of cheap or free toys to use.  Don't waste your money now on toys just wait and see what essentials you need.  

It would be nice if they had a cat tree or perch where they could look outside.  They can watch the birds and other activity.  Don't worry too much about them getting bored.  You can find ways to play with them.  Possibly they might learn to play with each other.  

Thank you for wanting to help.  Just take it slowly and they will be wonderful pets.  I hope you feel better soon too.

In addition to all the great advice @ShadowsRescue  gave you, check  out this article:
[article="33261"]The Five Golden Rules To Bringing An Outdoor Cat Inside  [/article]
Both cats are lovely.  It's wonderful that you're bringing them inside and giving them a home.

Feel better!  

Thanks so much for the help. I wrote down a few of the things to keep track of. I come with a few more questions ^^;;;
 

First once in my life i am trying to be the smart and responsible adult in the household. I keep trying to keep the cats out until i have had a chance to cat proof the house but my grandma keeps just letting them. I came out of my room just this morning to see little Spook strolling down the hallway going for an open room. Grandmother has Alzheimers so i keep trying to intercept her before she does it but my mom lets her because the cats make her happy. I want her to be happy but im over here pulling my hair because i want to make it perfect for the cats AND make it so the house is safe from them.

I keep seeing where it says to keep them in a room where they can't get under anything and i am wondering why? Last time i had cats i was told to let him go and hide under the bed or dresser(to be fair this was like 15 years ago)and that he would come out when he was calmer and ready. Has the information with that changed?

ALSO i honestly cant tell if they are already fix or not(or even gender honestly) Spook will sometimes, as he is rubbing on our legs, stand still for a second and i see his tail start doing the motion i know goes with spraying but doesn't actually do anything. Does this mean he is fixed or am i reading the tail movement wrong? ......Oreo has gained a lot of weight that we are hopeing is because he eats a lot at our house and 2 houses down at my brothers house(and other houses) Is there a way to tell if just getting fat?
 

You don't want the cats to hide as you want them to be social with humans and their surroundings.  By hiding they cannot do this.  You can give them a safe place to hide in a small box or the hiding box of a cat tree, but when they are under the bed or under other furniture more than just sleeping, they are avoiding humans and being socialized.  These cats sound very friendly.  Yet you want them to get used to your house slowly or it could lead to problems ( spraying being one of them).

A vet visit is a must.  You need to be sure of their gender first.  An unaltered male is fairly easy to spot.  With the tail straight up you would see two fuzzy balls.  A neutered cat you either will see nothing ( if the neuter was done quite young) or two smaller balls that look deflated.  Yet only a vet can make this call.  I would be concerned with the cat gaining weight that it is a she and she is pregnant.  I would get them to the vet next week.  If you do not spay/neuter them there will be territory yowling, howling, fighting and spraying from the males.  The females will go crazy while they are in heat.  Most cats will try to escape and get outside.  Being a responsible pet owner means spaying and neutering them.  Keeping them strictly inside is rarely an option.

Don't worry so much about making it "perfect" for the cats.  I think that will just drive you crazy.  Concentrate now on getting them to a vet and then making a nice cozy nook in your bedroom for them.  You don't need anything fancy.  Old boxes will work for beds or even just blankets or towels.  

With Oreo we know he was let out/dropped off when he was pretty young. My sister-in-law had been taking care it mostly before i moved up here. I know for a fact it eats a lot at my house and her house. I believe i was also told by her she knows another house that feeds him. We THINK it is a male, my mom said she thought she left testies before. Oreo has been seen laying around our backyard as other cats come and go to eat from the cat bowl and they leave him alone. We have never heard any fighting going on, i definitely know what that sounds like. When Spook first showed up Oreo tried to bully it off; poofy tail, low octave throaty growl, and a few swipes. Spook never let him chase him off. When Spook didnt react and run off we actually thought it might be that its was a female and Oreo a male and tried to separate them.

We haven't seen/heard any evidence of them fighting/attempting to mate when we know they are here. It has only been in the past week and a half that both cats can be seen sleeping on our back porch(on different sides though still)at the same time. Oreo is definitely top cat of our porch but he doesnt make noise much. I keep thinking that they might already be fixed, like they were fixed at a young age and then just let out or at least Spook might be. Him doing the tail wiggle but not spraying is making me think that.

I am really hoping and trying to get a chance to take them to a vet next week but we just got our big dog fixed and it was a major surgery because they had to go look for one of his balls. That was barely a week ago, so strapped for money.

The cats seems social with us people. They have no problems coming up to us, Spook is more a 'anyone can touch me and ill love them cat'; while Oreo likes to be petted on his terms. Oreo already knows our dogs and that he can take them. One thing we are trying to fix/make better is my moms dog scaring Spook. Our dog knows he can play with Oreo so he thinks Spook is the same, so we have been putting the dog up during the short inside visits to prevent traumatizing him. When they are outside he just runs next door and hides for a bit. I'll have to make sure i block off the beds and things. When we finally bring them in for good it will probably be my room they initially have to stay in and it only has a bed and a small dresser. Thats why i didnt think it would be bad to let them chill under the bed since its a really small room.

Y'all have been a giant help with easing my mind down about bringing them in. I was freaking out thinking it might be really hard since ive never tried to bring in adult strays. I grew up with cats but almost all of them were purchased as kittens or gotten from a friends litter(and one whos mom got ran over, that kitten was difficult because it was SUPER young)Been a big help here ^_^