If your looking for a cat/kitten to get along with your dog- your best bet is to go to your local animal shelter where they will know who gets along with (and some cats actually love to be with) dogs! For a kitten younger than 6 months, don't hold your breath. Even breeders (don't go that route for other reasons!) won't let you adopt till 3 months - depending on how good they are- no kitten should leave mom in an ideal situation, until they've had one distemper vaccine and if possible, the 2nd. No kitten can have it's 1st vaccine until age 8 weeks and if there are any cold symptoms, not until these are over. People who foster kittens for shelters will often not relenquish (and are not allowed to ) abandoned kittens until after the 2nd distemper (which covers a slew of viruses) because, if they have been without mom's milk and through her milk, virus protection, they are at high risk for death from the simplest virus and pneumonia.
Then new owners come back upset and lawsuits etc. So shelters are very careful. Sometimes TOO careful but just to let you know.
Even if you found a younger than 6 month old kitten- there's no guarantee he/she would get along with the dog- all animals have their own personality as you know- just be aware and ready for whatever! And Playitforward had good advice!