I am actually trying to do the same thing right now. I have a 50 gallon that I am making into a Cichlid community with Apistos and Rams. Someone I know actually got a Kribensis (African Cichlid) and it ate her guppies tales so she gave it to me. I don't think I will be keeping the Krib because she is MUCH more aggressive than the South American Rams. Plus they like different water as said previously.
I think I am going with Cockatoo Cichlids, German Rams, and any Apistos I can find around here. Let me know what you decide to go with.