I submitted a build request to GlassCages.com and after a thorough discussion with their team it looks like there will be some changes to the initial plan.
For starters, they highly suggested that I do not choose a rimless tank for an in-wall build, mainly due to the salt creep that develops and then goes over the rim and down the sides. So, it looks like the first modification will be to build a euro-braced tank instead of a rimless.
I still want to go with a rear, external overflow and they have recently developed some brand new manufacturing techniques to notch rear glass panel to accommodate the overflow which is only about 4 feet in length as opposed to the "Coast-to-Coast" style that is mentioned on their website. After talking it over with them I'm going with this newly-developed option.
The next part of the discussion revolved around the stand. They can build me a custom stand made of steel square tubing, powder-coated red with adjustable feet. It will also include a 4 inch lip that that will extend over the wall on the front and right side (as viewed from the fish-room looking out) so that the weight of the tank will not be on the walls. So far, working with these guys has been a breeze!