Have you considered silver dollars? How about 5 silver dollars, 6 zebra danios, and maybe something on the bottom like some kuhli loaches or corydoras? That way you have activity on every level of the tank with plenty of different shapes of fish.
why dont you take another look into African Cichlids if you look up with fish can go with eachother you can have a colour tank, and these fish are great to watch. if wont hurt just to check them out again