Instead of several schools of small fish, have you thought of a large school of them. Yes, with plenty of other tankmates. I have a 210 and am pondering the same thing. One large school could act as that center piece. Throw in a couple of larger fish (none that would eat them) and they should stay schooled and will look awesome moving through the tank. I just bought 32 balloon lamp eye tetras and love the tight schooling look. There is a video of them in both my journal and right here in the fish forum. Our tanks have the same foot print, mine is just a tad taller. Doesn't look like that many fish. So either I am going to add a second school of rummynose, or add more to this school.
I have kept kribs in a community planted tank before, and only during mating were the aggressive. Luckily they chose a spot in one of the corners of the tank to have their young. If you do, make sure you give lots of hiding spots.
~30 Rummy-nose Tetras, ~30 Balloon Lamp-eye Tetras, 2 Bristlenose Plecos, 4 German Blue Rams, 1 Rainbow Shark ~15 Amano Shrimp, 8 Roseline Sharks, 3 Clown Loaches, 2 SAEs