I have caught some catfish in the Lower Buffalo region and they become very active near darkness and at night. I've caught channel catfish and a few flatheads and have seen some channels or blue cats well over 10lbs while paddling down river. I would recommend finding a good wide deep section to set up your camp which I think would increase your chances of catching a big cat and tight line fish with your bait on the bottom of the river.
As far as baits go, night crawlers have worked well for me as well as live or dead bream which can be caught for bait during daylight hours using a fly rod with a popper, or the original worm and bobber.