That's a good idea. For long term, look at red eared sunfish, pumpkinseeds, or green sunfish. I'd still go with a very large aquarium since many sunfishes have large territories. For instance, a bluegill typically has a territory 6ft in diameter. They are very aggressive and will beat up on other fish that venture into their territory. Another obstacle you may encounter is the need for live food. Most first generation aquarium fish in general seldom accept prepared foods, so you'll need a steady supply of baitfish, worms, or crustaceans to keep their bellies full.
