Again, it depends on what manufacturer you go with. Some include clams other don't. If you choose one that does not buy yourself stainless band clamps. Try not tou use the typical U shaped exhaust clamp as they kink the pipe and make it real difficult to adjust later on.
Well, this weekend I installed my Magnaflow Catback I got from Partshopper a few months ago. It had everything I needed in it, except for some removable loctite (for the last hangar set-screw)....I didn't have any around (of course I had 3 bottles of the premanent stuff!!), so I used teflon tape, I hope that keeps them in....
IT sounds awesome! Well worth it for me Good luck...