If you're looking for doll eyes, we buy ours from Darice (
www.darice.com). You have to have a business tax ID to buy from them wholesale.
I also wholeheartedly endorse Jomama's suggestions. We use a ton of plastic spoons, marbles, ping pong balls, buttons, and the like. The important thing to remember is to use something shiny; the glint in the puppet's eye gives the illusion of life. Have fun!