they should be fine in a 125 rams are prolific once they get breeding. rummies are fast a school of them will help keep your upper tank strata occupied the firemouths will probaly not even pay any attention to them. some saifin mollies may work with some plants for the young to hide.How would Firemouths do with Bolivian Rams, Keyhole Cichlids, and Rummy Nose Tetra's?
What are others mates Firemouths could have?