As with alot of people on here, I recommend scrapping the aros and tsn idea. Also, no rays. I love my bichir--funny little fellas. Personally, I would like a 180 for a planted discus tank with corys and lemon tetras or serpae tetras. But if you wanted to go the bichir route, some dithers would be a good additive if you dont want anymore cichlids: SD's, barbs, etc.