If you like the fire mouth you could get 1-3 and get some small dithers like zebra danios. Ime fire mouths don't mess with plants so maybe make it a planted tank too. Not sure if mine were just very tolerant to plants or not but they were extremely mean to the other fish.
Thanks for all the ideas guys! Gonna be setting up the tank and getting the cycle going within the next few weeks. I'm thinking to go with one of the cichlids mentioned and maybe some tetras to keep him occupied. I'll post updates!!!
Alright so I've picked up a 40g breeder, I can't say why but I really have my eye on a Green Terror. Curious what dithers i could keep with him? I'll probably be able to get a 2-4" GT, was thinking tiger barbs as dithers, any other suggestions?
Also I've read that GT's grow fairly slow, is this true for those who have kept them?