If keeping the snake in your new location isn't a problem, then I say keep him!! Breeders ship snakes all the time and from what I understand, most make it to their destination with no problem and I'm sure the majority of them travel for more than 4 hours...not to mention they are being handled by a complete stranger who couldn't care as much about the snake as you do about yours. I would without a doubt take any and all necessary steps and precautions that I'd have to take just to keep the snake.

But, if you do decide to adopt him out, hats off to you for looking into the new owners and not just handing him over to the first person willing to take him.