a few suggestions of readily available fish
various combos
ebjd, jd, blue acara, severums (roketiel are nice), geos depending on species, firemouth, convict, sajica,
angel fish, appistograma, keyhole cichlids, dwarf pike cichlids
pairs
green terror pair, red tiger montague pair, salvini pair, cuban pair, not american but a paratilapia polleni pair
if kept alone
oscar, midas, rd , fh, trimac female, texas, chocolate, some vieja species