I used to us a treble hook and weight about 18 inches from the hook, but now I use a single circle with no weight. I usually fish for cats at Shabbona at night from the camp ground and this setup works well. If it is extra windy, i'll throw a weight on, but the chicken liver is pretty heavy already and I can wing it out there pretty well. When fishing from shore I use a medium or medium heavy spinning pole, sturdy rod holder that a 10-20 pound cat won't rip out of the ground, and a bell. I have been thinking about moving my cat fishing rig to a baitcaster with a bait-click and leaving the bell behind, but haven't made the move yet. If fishing at night, look for the more shallow water where the cats move into after dark. Shabbona is a great place to catch cats, just make sure your drag is set so they don't take off with your pole.
Mike