I like www.exoticnutrition.com. All the worms that I've ordered through them have been healthy and alive. They also send you 10% off coupon codes to use after every 2 or so of your orders! Sweeeet!!
I get mine from the eBay store of Kettle Moraine Wild Bird and Pet, because my phoenix worm deliverer has run out of mealies, and Timberline in Marion, IL has only waxworms.
Chrissy
P.S. Does it really matter whether the mealworms were originally for birds, not reptiles? I mean, as soon as you take them home, you feed them differently, anyways. (???)