If you can find them P. salousi might be a good alternative. they are much less aggressive then demasoni so you could keep most other mbuna no problem and the females are a nice electric yellow while the males share Demasoni`s striped black colour
What about the metriaclima sp dolphin (large demasoni). I am reading they are not near as aggressive. The hard part is finding some. Anyone have any experience with them?