Home made sandblast cabinets..lets see them

From the old one at the shop I used to work, I think you'll be disappointed in plexiglas or other plastic. It just doesn't take much sand to damage it. Rig up a little frame of angle iron and flat strap or even wood that you can easily take apart, and line with something readily available, say, "camper cap tape." See if your local glass shop does any large amounts of "standard" glass sizes, which may be popular in your area. This way you can easily pop in a replacement.