Just wanted to add a note about cutting holes in plexi. Personally I didn't have a BIT of luck cutting them with hole saws. May have been the saws I was using, who knows? I did have very good results with this:
http://www.grizzly.com/products/Adju...e-Cutter/G8964
I'm sure Grizzly is not the only place to get them. I did most of mine on a drill press, but did cut a single 120mm hole for the back panel in 1/4" cast acrylic with a hand-held drill. Very pleased with the results, just have to be sure the teeth are turned the right way so as not to leave a beveled edge where you want a straight one.
Either way, cut SLOWLY.
For cutting anything smaller than 2 inches, I have to recommend a Forstner bit:
http://www.harborfreight.com/cpi/cta...emnumber=40062
These things are like magic in acrylic (Plexiglass), they cut fine shavings and leave a smooth-walled hole. Excellent for smaller work.
(Nice work thus far, by the way, +rep)