You need to find a reputable breeder, not just someone who throws two dogs together and gets puppies. A good breeder will show all of the dogs that they breed to make sure that they are worthy of passing on their genes, they will make sure that they will not be passing on any harmful genetic traits to their offspring, they will also test the temperament of the dog. They do not breed for color, any breeder advertising a 'full blood red nose' or a ' rare blue nose' pit bull is not worth looking twice at; the red and blue is literally just the color of their nose and their is nothing rare about it.
It is NOT in the nature of the American Pit Bull Terrier to show any aggression towards humans, they were not bred for that purpose, and many make pretty lousy guard dogs because of this fact. It is extremely common for this breed to be animal aggressive though, they have a very high prey drive and should not be left unattended with other animals. I raised my dog around all kinds of animals to try to get him used to seeing them, I am confident that as long as I am on the other end of the leash he's fine, but that took sixteen months of constant practice and I still would not completely trust him alone with a cat. The breeders that advertise on this website would be a great place to start, they are not in it for the money and are very reliable. If they don't have what you're looking for, than I'm sure someone here can find what you are.
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Authorized Breeders - Pitbulls : Go Pitbull Dog Forums