The problem on the CAT is that it has two pipes going in and one coming out, so you will have to get someone to make-up a two-into-one if you cut it out. It is a single piece from the headers to just after it turns up to the rear pipe.
i'm hoping they come out with header that will bolt up to the 2bros pipe. all they'd have to do is make a system that would work w/ the factory exhaust and then it would work with any slipon. hopefully someone will