Welcome to BP.net!
Sounds like the crew here is pointing you in the right direction for doing your research and finding the information you need.
I highly commend you for finding a breeder in your area. You're son will end up with a much healthier animal and your wallet won't be nearly as light when it's all said and done.
One thing you asked about that has only been lightly addressed is the issue of what sex to get...Males tend to stay smaller and lighter than females, but since BPs are not a large species, either are easily kept and handled. Females usually cost a little more than males, but more so with morphs than Normals. Some say adult females are more prone to going on feeding strikes, but this varies quite a bit with each animal.
Of course, if your son ever plans on breeding, it's prudent to get a female first since they take longer to reach breeding size than a males. If breeding isn't in his future, there are really no down sides to purchasing a male.
Good luck! I look forward to seeing you around the Forum.