opaline gouramis can be nasty, expecially around other gouramis. sooner or later the opaline is going to start to go after the pearls, because the opaline gets bigger, much bigger. pearls only reach 4 inches long, opposed tot eh 6 inches that opalines will.
many tetras will be good tankmates. rummynoses, red eye, cardinals, lemons, and diamond tetras are all great choices. corydoras also make pretty good tankmates.