MakoJ, this looks like a fantastic setup. I'm about to order my tank and stand, almost certainly from the same builder even though it will have to be shipped to Arizona. My design is nearly identical to yours except for smaller size at 76L x 28W X 27T.
I assume your 1/2" glass panels are all tempered ? Not sure whether I should go with 1/2" tempered or 3/4" annealed, the latter being more expensive.
It is interesting to see tanks built with such a variety of materials. The PVC bottom is wonderful, no fear about a falling rock cracking the glass floor. Also there is a built-in starboard if setting up a BB tank. Choice of acrylic for the perimeter brace has puzzled me, but maybe there are structural advantages for keeping it one integral piece rather than four separate pieces of glass held in place with silicon. Certainly the use of acrylic is not saving any money, even compared with starphire glass. Since Tom obviously knows how to definitely bond acrylic and glass, might as well use it for the external overflow too.
Hope the delivery goes smoothly! Keep us up to date with pics.