Acrylic/plexi cuts very easily with a hand held jigsaw. They sell blades specifically made for acrylic, but a metal blade works fine too. The trick is to clamp it and keep downward pressure so it doesn't jump around. I have an art framing business and usually use the table saw and a composite blade for square cuts. The edges sand down by hand pretty quickly to get it to a point where you can polish.

A lot of the material I get for framing is this Arcylite brand, most often OP3. Your regional distributor will probably only sell directly to you if you have a resale certificate, but you can buy the material from an art framer or some other type of fabricator at retail too. They will probably cut to size for you at minimal cost.

I pay a little less than $3.50/sq.ft. for OP3.098 (about 1/8" thick). You might not need UV filtering stuff.

Using sharp tools and moving slow you should be able to drill and cut it however you want.

http://www.acrylite.net/product/acrylite/en/products/acrylite/uv-filtering/pages/default.aspx

Oh yeah check out that link- OP2 is the cast stuff. Might want to do some other google searches as there is a lot of other info out there.