I get all mine from the store i work at, and obviously greens and stuff from the local grocery/specialty grocery stores.
Zoo med makes the canned snails. They are pretty good, and are parasite free, i put them underneath a microscope in the biology lab at my college to check for all of that. Though they are pricy, they offer a good variety. I also use them for my blue tongue.
As far as roaches, the guy who brings us mice at work sometimes has them, so i get them when he has them (and are safe for food). The chicks do make a great variation in diet, and Rodent Pro has a great price on them right now if anyone is interested! I would order some if i didnt have a show here in two weeks.
Pics are down below of the 'girl' that turned out to be the boy. the link is here. http://forums.kingsnake.com/view.php?id=914270,914270
Also, i want to put the word out on a good nose rub treatment. Im sure this is old hat, but i never see it. Silvadine, which is a human perscription for burns, works great on Water Dragon Noses and is available via perscription from any pharmacty (tell your dr you have a burn from the stove and need a 50 gram jar of generic Silvadine called in, it runs 6 dollars with insuarnce) or from the vet.