it's hard to know how to proceed when I don't know what my needs *are*.
For what its worth, I think thats the best reason to DIY
. For example, I built my sump to increase water volume and to learn (I am very inexperienced). After experimenting and reading about my fish's natural enviornment, it was easy to adapt to a high one-way current and oxygenation system, . In your system, you could change media layout, flowrate, wetdry system, etc to your fish. Further, since big tank will be in wall, you could keep sump in adjacent room for easy water changes, filter upkeep/changes, water testing, etc. Of course, you could also do this with creative plumbing system and products recommended by TG and malkore. Just more ideas.