If you get a puppy and socialise it with the cat, it should be perfectly fine. They could even be good buddies.
I have a Patterdale Terrier and a kitty and when they were first together they would cuddle up (my signature below was made from a genuine photograph of the two of them). Now its a different story - the dog chases the cat at every opportunity and wants to play. The trouble is he plays rough and she doesn't. I don't think he would hurt her intentionally - they seem to get on better when we're not around, I think its more a case of she has matured and he is still a daft pup!

A recue dog is a great idea (and guarantees that you will be loved by PT forever!!) - welcome to the family