Welcome to the BOC, Tyler! As with most things fishing, there just ain't no best answer. What works best for one person may not work best for another; not to mention that it's often just a matter of personal preference. Size is generally going to depend on what size bait you want to use, what size fish you're after, and what type hook you're using. I have had excellent hookup rates using a kahle hook on my jugs, but I use a J-type Big-Eye Trotline Hook for two reasons: it has a big eye, making it much easier to change out a damaged hook; and it lasts longer...my kahle hooks rusted out after only one season, while my trotline hooks will last for several years. But, there are times when a circle hook will work better for me. When I want to put a jugline down around a bunch of snags, a circle hook will hang up a lot less often than a J-type or kahle. Now, with circle hooks, you need to remember that the space between the point and the shank has to be large enough to easily fit over the side of the jaw of the largest catfish you expect to catch. If it's not large enough, the hook will simply slide right on out of the fish's mouth, and it will swim away. And on any situation, you want your hook to be large enough so that your bait doesn't keep the hook from sticking into the fish. If you're in doubt, experiment! Try each type of hook on 2 or 3 jugs and see how each performs for you. Decide for yourself what best suits you, and the way you fish.
