hi
you can get the metal @
http://www.onlinemetals.com/
they will cut i think 2 cuts for free, or just use a hack saw. I think the reson why most wb companies don't use acrylic for tops, is one if it gets to hot it will melt and 2 extra cost? check out blade runners site his stuff looks real good (if you haven't seen it already.)
http://zerofanzone.co.uk