Okay, worked out some bumps, the tank is a "go". "Go" because it will take a very long time to set up.
The plan is this: buy the tank/stand combo, set up in my basement. Leave it there as I collect what I need for the current stock (1 Canister, 1 light strip, 1 heater, substrate) then put the 40b stock in it. Gather up the rest of the equipment over the next year in the following order: canister, heater, light, decor, fish. Boom, I'll be able to say by my 19th birthday that I have a running 75gal tank. Will cost me about 2grand when finished, but I won't be upgrading or altering it for years after that, so it will be money well spent. I'll post a build thread when I get the 75gal tank and stand.