Rainbows are one of the more docile CA cichlids but they still can be ornary when breeding. Having said that, if your tank is large enough you might be ok. The only problems I can see would be with the rams. I keep Nicaraguensis which are larger and slightly more aggressive than rainbows and they are fine with yoyos, rainbowfish, barbs, and a Raphael cat. I say give it a try but be prepared to remove the rams/rainbows if all you know what breaks loose.
