I'd also buy a couple frozen thawed mice first from your local shop first to see if your guy can convert, before committing to buying a large amount. You can buy a couple live from your local shop, and euthanize and freeze them yourself at home.

I like Big Cheese Rodent Factory. http://bigcheeserodents.com

It's much cheaper to buy packs of frozen thawed online in the long run, if you just have a couple snakes! Unless you really want to support your local shops.