If they're taking live sunfish, ever think of going after them with a fly rod. Given the size of the fish, an 8 or 10 wgt would be fun. Use a fast sinking line or sink tip. Tie on something like this or this sized up to about 5 or 6 inches
The one spot I fish they are very aggressive when it rains. I dont think it would be out of the questions that they would hit it. Just hard to do and I would use a 10 plus wt rod.
I had some fun last weekend using chubs and sunnies. My biggest was a little over 36" and I believe a male flathead... he was quite slender for his length.
I'm not sure how well a fly would work. Maybe if you could get some scent on it while it wiggles downstream in to holes.