http://burmanindustries.com/estore/home.php this is the company I order from and personally shop at (in Burbank). I go to them for my prosthetic/costume needs and also use them for the Labyrinth Masquerade Ball creatures. They're a friendly and knowledgable staff. They also sell various plastics for other finishing projects.
The Plastics Depot in Sunland/Burbank is the place I go to though for Resins, plastic molds, etc (for such things as making gems, glass-looking objects, and such).
The monstermakers site is good too though and fun to look through.
Thanks for posting it for folks! (Isn't that the site you or Chad showed us at our last weapon-building day?)
Cheers!
Adrianne