Will this be an all male tank? My advice is if you continue to do research to match aggression & size, and then get haps/peacocks that colors/patterns do not look alike, then IMO you're off to a good start. Obtain all your fish but know that as they reach adult size you will need to rehome the trouble makers. Also, avoid the hybrids like 'Strawberry Peacock', 'Firefish Peacock', and especially the OB's as they will IME be the first troublemakers you will need to rehome.