Plexiglass is a trade name for acrylic plastic. I had a small acrylic tank before and now I have a glass one. Honestly, I preferred the acrylic for its clarity compare to glass. Yes it is easier to scratch...you just need to be more careful. There are some special scratch removal kit that youcan purchase to remove scratches inside or outside the tank (even with the fish in it). For glass, once it is scratch, it is forever. In term of strength, acrylic is much stronger than glass given the same weight. I would prefer a one piece acrylic tank over one that is pieces together. Here is a link about working with acrylic.
Good luck. If build an acrylic tank yourself, please show it here
Well Ive been doing my research. Plexi is 17 times as strong as glass, yet if not taken care of, will need to be replaced after years of scratches. I've got a few ideas up in there air right now, if I decide on anything, I'll post it here for you guys.
Danny i would go with glass unless you have had problems with glass not being stong enough in the past. Because i would hate to have my tank all scatched up. Up to you though man. GL, just my .02