WANT TO CUT PLEXIGLAS "PLATES"

I'm thinking of a special design project.

I'd like to cut some plexiglas "plates" (does NOT need to be any high-grade type of plexiglas, either -- scrap issue will do) that fit into the inside of a standard 5-gallon bucket with about a 1/16" circumference clearance from the inside of the bucket. The "plate" needs to be thick enough to hold wet dirt without collapsing. I'll also need to be able to cut one 1" hole and drill multiple 3/8" holes in the "plate".

Is this doable with plexiglass? If so, how do I cut the plexiglas sheets? And, is there a supplier selling plexiglas sheets VERY cheap?

If not doable with plexiglas, recommendations for some other material for this project would be appreciated.

Thanks!

Linda