The pet store should know whether it is male/female and if it is captive bred. If they do not, then I would shy away from buying from them.
Snakes do just fine with being shipped. I think it is a lot more stress on us than it is on them.
BHB is a great breeder, but there are a TON of others. Take a look at websites and the adds on Fauna and Kingsnake.com as well.
Are you wanting a morph male? If so which morph?
We can help direct you from there.