sand , large smooth rocks and some drift wood with strong plants like java fern attached would look nice , also I know alot of rockwork is better for african cichlids but if you want to use rocks I would reccomend using pumice stone
there are techniques to make it sink and the small holes on the rock allow a place for good bacteria to thrive. and also pumice being so light there won't be alot of weight pushing against the tank.
there are techniques to make it sink and the small holes on the rock allow a place for good bacteria to thrive. and also pumice being so light there won't be alot of weight pushing against the tank.