Pan World is great, but I would go for more power to match the flow you need. I know you are already committed by purchasing the used DT. But if that DT (that cannot be drilled) is dictating several other decisions, I would reconsider whether you just buy, new, precisely what you want in a tank. So much in this hobby can be found used locally, as people upgrade lights, pumps, powerheads, etc. But tanks show wear and tear, and if it is not precisely what you want. I bought my tank pre-drilled for this reason.