Can you give me a couple of examples Ron? Thanks.
Sure. FWIW, I'd suggest a 48"+ tank at the minimum for long term success, larger being better.
Cynotilapia might be alright (afras)
Less aggressive Melanochromis species (johanni, cyaneorhabdos AKA "maingo" AKA "electric blue johanni")
Maylandia species (various zebras complexes, etc)
Labeotropheus species (trewavasae, fuelleborni)
Remaining "Pseudotropheus" species (elongatus, demasoni, socolofi)
With the exception of the Pseudotropheus dumping ground of nearly all mbuna once upon a time, I'd only pick 1 from any given genus to help avoid crossbreeding.