I'd get glass over crystal. Crystal has its place, but for an all around turkey call glass or slate are my picks. The blasted glass looks cool, so get it if you like it. But plan on conditioning your glass with a carborundum stone in the area you'll play it, because conditioning creates thousands if parallel lines that are critical to getting good sounds as the striker goes across them. Brookside sells a carborundum stone for a couple bucks.
Wood soundboards work fine. Personally I'd recommend starting with glass or slate soundboards on glass calls, and glass soundboards on slate calls.
Don't forget to get yourself a tube of plumbers Goop to glue your soundboards and surfaces in.
