I not a newbie at aquariums by a long shot but I just started up a new tank after having a very bad spell of bad fish from a bad supplier. But I recently purchased a 20 gallon high tank. Currently, I have a Florida Gar in there with three Gold Channel Catfish and three Firemouth Cichlids. I am wanting to get a couple more fish, any suggestions on another two or 3 small fish that would be compatible or 1 medium size fish that would be compatible.