No Flowmasters... they're chambered and only make nic sounds (unless you get the 1 chamber race versions (then it's just a wide spot in the pipe).
If I had kept my Cobra I was about to ditch the Flows for some LT headers w/ hi-flow cats and the Magnaflow Magnapack system (basically a cherrybomb) Very nice system and all SS.
Now that SLP is making the loudmouth I'd go w/ that on the stang.
Talking price... sack up dipshit, I spent $525 on my Borla catback and that's on the cheap for my car. The Corsa race Titanium system costs $1200 for only a catback, the average is $800ish. Gay ass Corvette markup.
Oh yeah and talking about the car being limited production etc... shit it's just a slow Moostange

Seriously though I'd rather take the stock system off in one piece so you could return it to factory stock if you ever wanted to. Get a complete system and just bolt it in.