When we built a stand for a 100 g we used massive amounts of 2x4's and 4x4's for the corners. We just picked up a 210g setup off of Craigslist the tank is extremely heavy the stand came from our local fish store and it barely has any lumber mostly made out of oak plywood. We way overbuilt our homemade stand after getting a good look at a store bought setup.
I would PM Brookster123 and have him take a look.
Those appear to be 2x4s running horizontally and (1x3?) running vertically. The vertical studs might be on the smallish side but the number of them may make up for it. It's a good design to have the weight resting on the stud itself.