There's also a local source for abs plastic sheets in Aberdeen, if you want to go that route for sluice boxes and such. It just takes a heat gun and simple wood jig and some clamps to bend it. Mine are all made this way and they are tough and light weight.
Plastics West inc.
400 W Curtis St
Aberdeen, WA 98520
Yep. Abs is cool stuff to use.
A skill saw using a fine tooth blade and a straight edge cuts it, and a $10. heat gun works out a lot cheaper....especially since once you see how easy it is,
You'll be making all kinds of useful stuff you haven't even thought of yet..