Sometimes I daydream about different types of aquarium fish that would make excellent bait fish ( terrible ADD) and I've found a few fish that would make excellent schooling bait fish in Southern ponds.

Zebra Danio- max size 3", slender streamline body that is raised in outdoor ponds for Aquarium use.
http://www.liveaquaria.com/product/prod_display.cfm?c=830+881+941&pcatid=941

Giant Danio- Max size 4", stocky streamlike body that also thrives in Florida commercial ponds before becoming an aquairum pet. http://www.liveaquaria.com/product/prod_display.cfm?c=830+881+945&pcatid=945

Australian Rainbow Fish- Max size 4" also very similar to the Giant Danio.
http://www.liveaquaria.com/product/prod_display.cfm?c=830+886+3199&pcatid=3199

Also many Guppy, Mollie and Swordtail fish (same as Gambusia) will thrive in outdoor ponds in Southern climates.

One day when I finally get my own pond I will try introducing these fish into my pond, with their small, slender size they cannot over-run a pond. Hopefully anybody looking for a new non-typical bait fish will find this information helpful.