Hehe...I already own paradise fish, so I know of their hardiness and demeanor (they're actually much less obnoxious in harems or groups...they're much more interested in heckling each other than in bothering tank mates). I am hoping to see if the apartment landlord allowed me to keep a small (4-5 ft diameter) kiddie pool from mid May to mid September out on the yard, and try to breed the fish in it. Knowing PF's, they could probably spend half a month out longer on either end, and Macropodus Ocellatus would probably do well as long as I took them in before the freezing began.
Native fish are also an option, yes...but I REALLY like anabantoids, especially paradise fish. Lots of personality, and their interactions are fun to watch.