What is the best paper for use with light-boxes?

Additionally if you know any links for help in building the actual light box that would be helpful. I need to know what kind of paper I should use to print my photographs on that will be viewed through the light box? I've heard Epson had a special paper specifically to be illuminated through but haven't found it. I'm considering Vellum, Transparencies and Epson Enhanced Matte.