To build an enclosure for my Taig

Hello again! So I now have my Taig mill, and my servo kit in on the
way. In the mean time, I'd like to start building an enclosure for my
mill. I was wondering what material I might want to use for the base
to anchor the machien down and absorb vibration.
I know of a machine shop closing down around here that has a nice
granite plate, I think its 18x12 that I could snag for $50 or so...
do you think that work work to bolt the machine to?
Failing that, I was thinking just some 1" thick plywood for the
bottom?

For the sides/top/doors, I was just going to get some 1/4" lexan, and
bolt or glue it together, use some angle aluminum in the corners,
etc. Is that a good way to go? As always, any advice is welcome and
apprecaited.

Thanks,
Andrew Pullin