KGeorge...hopefully Jenluckenbach will chime in with me...as she has a multi-multi cat household...introducing a kitten to a two year old should be a very smooth transition. I have six cats..and everyone gets along well, and pairs up with another one. The only downside is that the younger kitty will probably bond more with the two year old than with you...though that hasn't happened to me.

I think two cats is way more easier than one, and with the amount of cats/kittens in need, DO IT!!! Good luck.