As long as you keep just africans or specialize in a particular lake there really are no limits to what kinds of africans you can choose with the exception of the very largest of species . Just be sure to match temperments and dietary needs if mixing species.
You can do :
Most commonly found Malawi setups :
Malawi Mbuna (highly colored , highly aggressive rock dwelling cichlids)
Malawi Haps (Larger cichlids, Stunning male colors, active swimmers)
Malawi peacocks (Medium sized, highly colored males , flashy spawning, active swimmers)
Malawi Mixed Hap and Peacock (Go all males, super active , gorgeous colors, super active tanks) Its not a good idea to mix in mbuna here)
Malawi species only breeding colonies of your choice (too many to list)
lake Tang setups :
Tang shellies (interesting often colorful tiny fish that live in shells)
Tropheus (Larger and aggressive , species only and if your aexperienced cichlid keeper)
Brichardi (Small to medium size, species only breeding colony, do not mix with other species ever)
Various other tang setups/species too many to list
Victorian
Im sorry , i am least familiar with these species but have seen gorgeous highly colored cichlids of all sizes and temperments posted here and elsewhere. Not 100 percent sure but i think they might be harder to get or rarer in general with a few species common in some shops.