All dwarf breeds would work good. You can have 2 (or maybe three if heavily planted) pairs in your tank along with other community fish. You might be able to do a pair of firemouths but that might be pushing it a bit (depends if having tank mates with them or just the firemouths). But look at the forum New world cichlid index and pick out your fav (rams, apistos, keyholes, checker)