I fish lakes, so I go with the carolina rig mostly. Egg sinkers. Depending where I'm fishing and how far I have to cast depicts on the size of sinker I use. I am thinking of getting some sinker slides and seeing how I can use different sinkers with the carolina rig. Would probably be less resistance on the line when a fish takes off.
Flatheads is carolina rig, size of bait usually depicts sinker size. I also like a slip bobber setup also
It does sound like channels. Maybe downsize your bait and see if you can get a hold of one just to see what may be hitting them. I caught about a pound maybe pound and a half largemouth on a small goldfish about five inches long a couple of weeks ago.
If your using clickers maybe turn them off and tighten the cast control knob a little and see if they may take off with it that way. But the flatheads shouldnt be too finicky right now.
Got a couple from Botton Dwellers. I put my Kalex reels on them both, So far, I have been impressed with them. They make a good channelcat rod, I bought them to use on the boat, but I took them out bank fishing, They seem to cast very well, I have only caught around a six pound channelcat on them, but they did the job and they have a good action to them.