I don't recommend you rebuild your brake calipers unless they are too expensive or too rare to find on the open market. The truth is that a caliper rebuild kit is pretty much a couple of rubber seals: one seal for the caliper piston, and one for the dust boot. The problem is that often times the caliper piston or bore is so pitted up from corrosion that it will never seal properly when you're done with your rebuild. You often don't find this till after you've got it apart or after you try to use your freshly rebuilt part and you find out it leaks.
If you're considering rebuilding your brake calipers, don't. You're better off getting remanufactured units and installing them. That way you know you can rely on them to do their job. To give you an idea what you're up against, here's a video I made on brake caliper dissection.