Thanks for all the great comments, folks! You all have me more enthusiastic than I'd been able to muster solo.
Kayen: Not sure, but it'll likely include an Eheim as I've had a few over the years, pressurized Co2, and all the ADA/Swarovski trinkets I can fit.
Dollface/Francis: I think the height does lend itself to that type of setup, although the proportions are certainly not golden. Still, if no one tells, I think it might work.
Graig: C'mon, share bro'. You'll feel all warm inside. I have no doubt the tank would turn out better if I took you up on your kind...offer, but I've been promising my daughter I'd put fishies in this thing for the longest (that's real dust you see in that tank), so fishies we're getting, dammit.
Haagenize: As mentioned in the OP, that's temporary and I'll be going to sturdier brackets and a shelf. As for hiding the equipment, I'll be using a cloaking device, but I've yet to see what the electric bill will look like so I don't know how viable a solution that'll be long term. Of course, such a device makes stuff even more susceptible to getting knocked over (don't ask!), so nothing's final. I do plan on extending the tank shelf another foot or so past the tank on the right side for equipment. Have to move some geetars in that case.
UG: I love that idea, and have always wanted to try big, emmersed growth. I wonder, though, if that would be compatible with a lush carpet given the limited front-back depth, Still, I'd take a combo of low-light submerged growth with some impressive stems sticking out. Couple hanging pendants for light.
Thief: As is my wont, I neglected to take advantage of having the tank drilled w/ overflow when it was being built ("planning ahead", its practitioners call it). As I recall it was about $200 shipped, which is not too bad here in ADA territory.
clwatkins: Didn't get it from there, although I'm reticent to say where since I probably wouldn't use him again. Workmanship's fine (and the edges are nice), but lack of communication once someone has my money is frustrating and inexcusable in a present filled with instant, effortless messaging in many forms.