Have you considered a wet/dry filter (sump)? For a tank that large, a wet/dry is very efficient. You could put the sump and pump under the stand. Also, if you haven't bought the tank yet, seriously consider acrylic. Much more expensive than glass, but much nicer, lighter, and virtually unbreakable. They work well with sumps as you can drill inflow and outflows into the acrylic.
Roger (always pH) Lederer