1st-Good luck with the "I must have that cat" speach.
2nd-Congratulations. (because you will win after that speach)
3rd- SLOWLY is the key word for introductions. Let new kitty have a room of her own until she is comfortable with it. Swap items that would have each cat's scent on it (towel, blanket).
Don't be in a rush to show the cats to each other, let new cat bond with you and her surroundings before throwing another animal at her. Then do so only under supervision.
I am living proof that you can successfully introduce animals of all different personalities to each other and have it work.
GOOD LUCK!