2013 Mustang GT Flowmaster Outlaw Catback + Headers + Midpipe

Hi all, Im still fairly new to modifications and I dont know if this question has been asked before or not but here it is anyways.

I currently have the Flowmaster Outlaw Cat back exhaust on my 2013 Mustang GT and planning on installing headers and mid pipes (or whatever other parts are left to have a full aftermarket exhaust system).

Im leaning towards the American Racing Headers Long Tube Headers 1-3/4" With Catted H-Pipe 3" Stainless Steel as Ive heard good reviews about them and that they make a low rumbley sound in contrast to a raspy one.

Will these parts fit together? Or does the Flowmaster Outlaw Cat back already come with the X-pipe? if so what is the part between the X-pipe and the headers that have the stock catalytic converters?