A have heard some pretty negative things about a couple of those sites, backwater and first choice in particular. I've never personally ordered from them though so I can't say from experience. Just make sure you read up and look for reviews before ordering stuff from a supplier.

There are also a couple adds on kingsnake.com as well.

kingsnake.com Classifieds: Pipa Pipa Frogs (#3227) and kingsnake.com Classifieds: Pipa Pipa (Surinam Toads)

Good luck getting your toad.