Bringing home TWO new cats?

Is it too much? Should I forget about it?
We have a new kitten coming at the end of the month from a breeder (Maine Coon.) He will be 15 weeks old. I have one cat at home who has been an "only cat" since I've had her for the last couple of years, don't know about before that...
The problem is, I fell in love with the kitten's mother who is being "retired" and is looking for a home! (Here's a photo of her: http://www.koontyme.com/cat_images/woopie.jpg)
I really like her but I don't know if bringing home two cats at once is going to be just too much for our resident cat? We were planning to have the new kitten and our current cat stay in different parts of the house for at least a few weeks after we bring him home. We have an upstairs "apartment" where my brother lives which has a cat door at the top and bottom of the stairs so we can easily block the cats off from each other.
Do you think adding two is just too much stress? Should I try to forget about the mother cat?

I think two new cats would be ok, but after the intitial confinement and introcuction steps, I would make sure that the resident cat is reminded everyday that she is top cat, and do it in front of the newbies. pet her first, feed her first etc. that way she will have no reason to be resentful.

I don't see how adding two cats would be a problem. You're already going through the whole introduction thing, you might as well introduce two new cats!

I'm assuming you want to bring home the kitten and mother at the same time? If that's correct just confine the mom/kitten in the same room and do the steps of introduction slowly.

Is the kitten male or female? If male, you want him neutered very soon. (or spayed if female).

Now I'm assuming the mother will be spayed when you get her? If she's already been done, you shouldn't have any problem with her as she won't be hurting from the spaying.

You MAY have some issues on who is boss female cat. Whole cats are top cats and if she's been recently spayed, she may feel she is STILL top cat, so introduce the 2 adult females very slowly. They will have to decide who is boss. It might not be your resident female. You can't decide who's boss in the end - they will work it out.

Just be sure to show attention to the resident cat first, whether or not she winds up to be "top" cat

Yes, the mother has already been spayed. The kitten is a male and he will be getting neutered before we bring him home (it's one of the breeder's requirements, all pet kittens are neutered before they go to their new homes.) He will be 15 weeks old when we go get him.