Well, first, these are mostly aggressive fish. Two, getting one of each assures even more aggression as fish in groups of their own species tend to be less aggressive than individuals. Three, if you get babies, you are not going to be able to tell what sex they are. Four, Texas and Terror and Jack Dempsey cichlids get big and oscars get HUGE. Never heard of Metrops.
My recommendation is to set up a nice tank and pick one cichlid species to inhabit it. Firemouths are attractive and interesting and don't get too big.
Roger (always pH) Lederer