First, remaining from what? Second, angels are good for color and swimming but you need a bigger tank. Third, Do you have LR
, or corals or just non-living decorations? Fourth, What kind of fish do you like? What general species? You could find a fish from that species. If we assume your percula is 2 inches as is the Royal Gramma, a threadfin butterfly fish would be good, but watch out Starfish! They grow to 6inches. Then you could get maybe another percula for your other one. That is what i would do.