Instead of Micropterus species, which make great single specimens (because they are serious bullies), you should try Moronids aka temperate basses, like white bass or yellow bass. They are very active and the one I take care of (a yellow) is high on my list of cool fish I've kept. You could also put them in with a nice collection of sunnies with no problem. If I were you, I'd make it a goal to either have every local type of sunfish, or a large group of longears or other attractive species. Bluegill just don't really do it for me (even though I have a couple in my pond). I think the bullhead idea is a good one, too.
You can also get true perch up there like yellows, I think. Pickerals might also make cool specimens. IMO the coolest thing about native tanks (or ponds) is that you can put fish in them that are local and you hardly ever see in tanks. In other words, you have lots of options.