Dan . . . . I am going to assume that your residence is rather permanant. If thats the case, and you dont plan on moving for a while, I would put some serious thought into a steel stand. Not the whole thing, but the frame and supports, and then put a facia on the outside be it whatever you please.
Just a thought here . . . . 480 gallons of water at 8 lbs per gallon = around 3840 lbs. But you have to add in the weight of the tank, the weight of the lighting (unless you do a pendant, which I personally would). But you are not going to have 480 gallons of water, more like 300 with a lot of sand and rock. You tank will be well over 2 tons when its done. Personally . . . . I would trust nothing but steel beams. I can point you in the right direction to a small little engineering firm thats local if you're interested. I cant even put an estimate on cost, but I dont think that steel beams are all that expensive (relatively speaking)
justin