This is meant for very small collections (5 or under) but I'd recommend investing in an insulated reptile box and heat packs. Then all you need to do is put the heat pack in the shipping box, cover it with crumpled newspaper and put the snake in a cloth reptile bag and in the insulated box.
Definitely should have a couple of these just in case: http://www.shipyourreptiles.com/shop/heat_packs/product