Feral Colony flea/tick/worm prevention

Hello!

I am a feral cat caretaker in Baltimore. I have a colony of ~12, with some occasional new visitors here and there. My current solid colony kitties are all spayed/neutered. Some of them I can now pet, but many of them won't let me touch them at all. I was wondering if anyone had any suggestions for flea/tick prevention and de-worming. 

I have one old kitty named Old Man Winter who I had neutered about 3 years ago. He won't let me touch him, but when I took him to be neutered a while back I was told he has a flea allergy. Now he's so itchy and I'd love to find a way to give him safe and effective flea prevention... I was looking into a brand called Capstar but wanted to reach out first. Ideally the medication would be oral, I would mix it into a small amount of food, and watch from my window that he specifically eats it. He will watch me put food in his bowl and as soon as I go inside he will run up and eat, so I know an oral medication could be monitored. What do you think? 

I'd also love to find a safe, oral deworming for all the cats, as I'm sure they have worms. Many of their bellies are a bit bloated, but otherwise they're a very healthy and happy colony. Any suggestions for oral dewormers? 

Thanks in advance! 

Here are some pics of my babies, including two boys on my couch (I think they're brothers) who aren't so feral anymore  

What beautiful cats! Are you able to sit close to them while they eat? I used to be able to drizzle Frontline Plus between my feral cat's shoulder blades while he was eating his favorite meal of roast chicken breast while I sat closely beside him. He never allowed me to touch him, so I had to be sneaky about it. Sometimes he'd get quite annoyed and hiss, but I managed to do it. Capstar has the great convenience of being an oral medication you can put in their food, but the drawback is that it only destroys the current fleas while a topical, like Frontline, works for 30 days.

Drontal is an effective de-wormer. If your vet won't prescribe it for you because he hasn't seen any of your ferals, there are sites (Canadian) where you can order it online. I think it must have a bitter taste, though, so it would need to be mixed with tuna or something strong.