Peacock bass would be an option for sure, especially kelberi/intermedia/occ imo.
im searching for a similar size tank to house a pair of red terrors and a group of large characins such as gold wolf fish, red tail barracuda, or SDs.
something like a pair umbees, red terrors, or other large pet cichlid would be my vote.
with the morays I would totally throw in a lionfish (as long as it’s not a tessalate or green, have seen those two eat lions) those are some of my favorite fish I’ve ever owned.
I might also point you to a small grouper. Minis, coney, and the majority of other cephalapholis would be interesting with maybe 2-3 morays.
perhaps you would get some of the hunting behavior.
a lot of people may say that the tank is too small for some of the stuff I recommend. (Such as the grouper or umbee) but I’ve noticed in captivity large predators rarely hit 1/2-3/4 of the recorded size. And with proper feeding and enrichment they will thrive with enough footprint. Ie 3x5.
Interesting I didn’t think peacock bass would work but they would definetly be sweet. So if you were me would you go freshwater or saltwater with this? Honestly both have cool options and it’s super hard to decide.