Those are really different fish.
Frontosas are large growing and fairly docile in an established aquarium. Relatively easy to care for as long as you consider their needs. You need a minimum 6ft tank for Frontosa. Tank mates for frontosa should be large enough to not be eaten by them and not too rambunctious.
Tropheus are an aggressive active fish. They should be kept in a colony to reduce aggression. They require fairly specific attention to diet and water quality but are not that difficult to keep for the experienced aquarist. Tank mates for tropheus can be difficult do to there aggression levels and feeding habits. Typical tank mates include Petrochromis, Julidochromis, Spathodus or Etetmodus species provided sufficient space is available. Tropheus need a 48"x18" tank at minimum
