What kind of fish can live PEACEFULLY with a south african malawi cichlid?

have a yellow cichlid that i bought at walmart last year that was advertised as a south african malawi cichlid, so due to walmart fish experience it could be any type of cichlid. Its a bright yellow cichlid with very faint black horizontal stripes. Right now its about 3.5 inches long. (if any one knows exactly what kind of fish this ease please tell). Anyway, i have kept it with 3 other cichlids( all of which is has driven to death by constant bullying) it has been kept with two different orange malawi cichlids and a jewel cichlid( i bought this b/c its an agressive fish which i thought would hold its own. at the store this particular fish was the dominant fish in the tank. ) does anyone know what kind of fish would live peacefully with my fish. I want a Pacu or an oscar but those would probably kill it.