IMHO, the concerns about scratches and bowing of Plexi (Acrylic sheet) are overstated.
I've had a piece of Acrylic installed in my cab for about 3 years now with nary a scratch on it. It doesn't bow either. Just use common sense when cleaning it. I.e don't use the wino method of wiping with crumpled newspaper

. A soft cloth and some decent mild cleaner will work fine.
Unless you are poking at it, you can't tell Acrylic from glass, so if you are putting your cab in the local laundr-o-mat or building a cocktail unit, use tempered glass. Otherwise, use the material you like best, can afford and has the optical properties you desire.
RandyT