I say if you're inclined to spend the money on salts, then go for the FOWLR. I think for puffers I'd want to go with a tank with an 18x36" footprint, but that's just me. Now a brackish tank with Celebes Rainbows, bumblebee gobies, and some black mollies might be really cool. I thin vals can handle 1.005, which would be fine for all of those. Something odd like waspfish might be cool (LiveAquaria was selling them as Panther Gobies). At them moment, I might be tempted with a 36 BF to put down sand and river jacks, a bunch of branchy driftwood, a small stand of vals or a dwarf lily, and then a trio of apistos, a half dozen cories, a rineloricaria whiptail, 10 or so marbled hatchets and 10 or 20 pencilfish.