American Pit bulls are very solidly built dogs, derived as a variation of bulldog and terrier crosses that came out of 19th century England and Scotland, meant to combined the speed and agility of the terrier, with the strength and athleticism of bull dogs.
They were originally used to bait bulls and bears, but when these practices were deemed inhumane, they were then used as guard dogs and for the cruel purpose of underground pit fighting for entertainment and money.
Eventually, the dogs became increasingly domesticated with people coming to appreciate their extremely loyal and naturally loving, gentle demeanors. They were also use in WWII for the purpose of delivering messages on the battle fields.
My own experience with all kinds of pits, is that raised in a loving environment, they are gentle, loyal, fun dogs. I rarely find myself having to muzzle pits on visits, as most are very friendly. They are also very intelligent and quite trainable.
The average life expectancy of an American Pit Bull is about 12-14 years, making it one of the longer lived large breed dogs...this fact makes them attractive to many a dog enthusiast. They are prone to a congenital deformity of the hips known as hip dysplasia, which can be debilitating. Therefore, I always advise when researching breeders, that they provide documentation of OFA certification of the hips. OFA is the Orthopedic Foundation for Animals, and below is there website:
They are also prone to demodectic mange (a non-infectious mange of the skin), congenital heart defects, a malformation of the elbow known as elbow dysplasia, problems with the patella (knee caps), and thyroid deficiencies.
The good news about all of these diseases, is that OFA provides certifications for most of them, offering a guarantee that the parents have been screened for these disease, and therefore less likely to pass them along to the offspring. THIS TO ME IS THE SINGLE MOST IMPORTANT ASPECT OF SELECTING A GOOD BREEDER. The more OFA certification for the aforementioned disease that a breeder can produce, the better.
The second part of your question is which kennels I may recommend...and that really depends on your intentions with the dog: pet, show dog, or competition/agility dog. While I do not have any particular kennel that I may recommend, a simple Google search "American Bluenose Pit bulls" will offer a large list of kennels out there, and you may decide which one to go with based on what you are looking for. Whether selecting for pet, show, or performance, the most important thing to assure that your will have a well healthy, long living dog, is to demand documentation of OFA screening for the parents for the prospective puppy.