Around the great lakes and in larger inland lakes there are healthy populations of rock bass. They grow similar in size to panfish, but have more slender (fusiform?) bodies. When young I imagine they would be a great forage source for big bass.
I hear nothing about raising them in fish farms, not much online about how well they reproduce in ponds or how many offspring could/would survive. They are typically described as being in moving streams near deep holes and hiding under cover of rocks, but I have caught them routinely in the same habitat where bluegill/sunfish live, mucky bottoms, shallow waters with vegetation (clearly no current, no deep holes and no rocks).
They are fun to catch, scrappy fighters, and seem to tolerate muddy bottoms and more turbid waters.
Since they probably can't be sourced commercially, I would be eager to hear if someone who has smaller forage ponds (where they could do rockbass and FHM/Shiners only plus insects, crayfish, etc and where they could observe spawn success and create a sustaining population) could make it work well.
I've witnessed them being aggressive and hitting anything even things too big to fit in their mouth, this may be a spawning specific aggression feature but I think they in many ways are the GSF of the bass family.
I see there is a southern variety that may be more suited for warmer ponds: Ambloplites constellatus, a species of rock bass from the Ozark upland of Arkansas
Great Lakes Rock Bass adult:
Young rock bass:
Ozarks Rock bass (pretty fish!!)