99% of ball pythons really will be docile animals and are about the same. Very few are actually defensive and snappy in terms of usual temperament. You can check out faunaclassified to find snakes/big to hobby breeders, and ask them about their animals to see which one they think is the most docile for you.
For personal recommendations, recommend Nick and Victoria at MCMB... http://www.mcmbballs.com/ You can find them on faunaclassified once in awhile too, which is where I found them.
They're just a hobby breeder, but my experience with Nick was very good. He's very detailed, honest, and articulate in our emails back and forth about his animals and their temperaments, and you'll find that when you talk with him too. I trust them a lot. They also have good prices.