I am fortunate enough to know several people who have integrated cats before, so have received some good advice. My cat #1 (Luvbug) is ...uh... ornery, to say the least. She still hisses every time she sees Missy (the house owner's cat). They have come to a decent truce of sorts in that one stays on one floor mostly, the other on the other mostly. We think we've found scabs on both of them, but there hasn't been enough bloodshed or tufts of fur to be sure of any out-and-out battles.
The recommended methodology is to keep them in separate rooms for two weeks -- they'll smell each other through the door. Then introduce them in controlled circumstances (hold one, bring it into the room with the other, and vice versa). I'll see if I can dig up the email and quote it.
The thing that's going to be difficult is that this little guy is only about 7 weeks old, and Luvbug is 14. As in, years; as in, a senior citizen. He's going to want to play; she's not. So yeah, there'll be blood, I'm sure. Probably mine.
The other thing is, the little guy is a people climber, so if I'm holding Luvbug and bring her into the room with me, and he starts to climb me, she might try to kill me via acupuncture. I have a feeling that one will be a two person job.