I definitely think, after watching the auratus, that the brochis are gonna go to a safer home right away. I've got a bid in on a 20 gallon and another 30 gallon tank on ebay, if I don't win those I'm going to pick up another 20 gallon and get the brochis into it. The auratus isn't big enough yet to fit a brochis in his mouth, but he will be soon.
Right now the Red zebra and the Yellow Lab are about three inches each. The auratus is about two inches and MUCH smaller bodied. (ie, the others are about an inch and a half from dorsal to pectoral fins and the auratus is about half an inch)
herefishy, thank you for your input, I do respectfully disagree about the 28 gallon being insufficient for any stocking at all. Once the barbs and the brochis are relocated that will be a mbuna only tank, and I'll likely be adding one or two more fish. The yellow lab and red zebra that I have are relatively docile for mbuna, I'll be looking for similar qualities in any other fish I might add (note, "relatively docile") The auratus, well, he might end up in a new home. He's a little spitfire already.
I do, however, love your idea of the dwarf riverine cichlids from West Africa. The new 30 (provided the gods of ebay smile on me) may be turning into a river tank.