Gamakatsu Octopus Hooks 5/0 and 6/0 will work I am sure somebody would say that is not right but I have caught fish on them.
4 baits per crab I don't like to skimp on bait. Bait is the point of contact between you and the fish. The fish does not care how fancy your boat is or how pretty your custom rod is. They want to eat, spend more money on bait and less on stuff.
I use #3 or #4 Mustad Virginia Hooks and I'm a little bit more cheap than Mr. Wes Blow, I get at least 6 baits out of a typical blue crab. Pull off the shell, cut the body in half then, using scissors, clip out your baits making sure you have at least one knuckle in each bait. Thread your hook through the knuckle and through the shell and you're ready to go. Oh, you may also want to trim the legs down or rubber band them to your line or the bait will spin and mess everything up.
offshore I usually go bigger with the hook size of course....so 4/0 or 5/0 good for offshore while 3/0 or 4/0 is a good size for the bay.....I tend to like the gami's best :0)
if using a treble size 1/0 4x tra strong VMC works nicely or size 2 4X gamkatsu