yes, your tank is overstocked. Just with the 3 snooks even. And a 6 foot tank would be big enough for 1 peacock bass, maybe a pair, but that might be pushing it. And as for lasting a couple months in that tank, I would assume that a few if not alot of your fish will die by then, not trying to be cynical or mean, but thats just the facts. I would seriously consider relocating some of those fish.