This isn't exactly what you asked for, but... a good alternative to small waxworms are fly larvae (maggots), which I order occasionally from grubco.com. Given the current hot weather,:evil: that may not be an option until next fall, though.
I used to order jars of waxworm culture - basically, a jar containing medium + waxworm eggs that would hatch and rapidly grow into waxworms of various sizes. I can't remember the name of the person I used to order from, but I can hunt it up if you are interested.