Aloha Nate,
Hey, you are one of the old timers here.
If I'm not mistaken, you started in the hobby in the 90's and joined the WMAS soon after that, right? I've been thinking about you lately, because of your helpful advice here in the forum. Also wondering how you ended up in Riverton WY.
If it is a glass tank with a bottom frame, truth is, vertical support on each corner is all that is needed for tanks 48" long or less. Of course, bracing at the sides to keep it from tipping/sliding over is also important.
As you know, 2x4 construction works very well for many years and does not give in to moisture.
Sounds like you are wanting a stand that is larger than the tank, right? Using some free materials at your disposal? In my experience with framed tanks, so long as each corner is level and solidly supported it will be fine. The top of the stand can even bow in the middle so that almost the entire length of the tank frame is unsupported, but as long as the four corners are solidly supported, it will be fine. The reasons for this have to do with the structure and physics of the glass box of water.
I currently have a 40 gal breeder sitting on the two footboards from two kids bed frames. It was a perfect fit at 36" long. With the top frame ripped off of the tank some people might wonder, but because the four corners are solidly supported it works.
Mahalo,
Mark
P.S.
Avoid high centering at all costs. Again, because of the structure and physics of framed glass boxes filled with water, even just a fraction of high centering along the length of any of the four sides can cause the glass to crack sometime down the road.
Edited by Mark Peterson - February 17 2014 at 7:07am