3 months later I finally got around to finishing the framing of the stand for the big tank. It cost me ~$10 for screws and the rest was all just lying around the house from previous projects. The legs came with the original stand which was way too thin which explains why the base broke out of the tank. And yeah, ok, when it's finished it'll have cost a bit more but for now that's what it owes me.
I might need to think about a little bit of bracing on the ends and maybe a bit on the back but i'd have to buy the wood for that at this point and that feels like cheating. I'll then add a bit of mdf/particle board to the shelf and top of the stand, a couple of licks of paint and I can then start on the tank itself.