this will give you links by feeder, state, country - anyway you want it.
http://www.feederfinder.net/
I second the vote for mulberryfarms as they carry a lot more than just silkies and hornworms now. great customer service and quality insects.
grubco.com has a sampler pack that can be a good choice except that they include "mighty mealies" which are frowned upon (they are bred using growth hormones).