More fish for 29 gallon?

[hope]

Just curious if I could add anymore (either a small school, or a centerpiece) fish to my 29 gallon tank? We have 8 tiger barbs right now and 4 Platies.

If I can't, that's cool - it's a pretty active tank, but I love the concept of centerpiece fish

 

[sarcare]

It seems to me that tiger barbs do not do well with most of the fish considered to be "centerpeice" fish. They also get to be big chunky fish.