I have the Flowmaster catback, it is been available for about a month now, and it can be seen on the main page of their website. Comes in 2.5" mendrel bent aluminized steel piping, two Delta flow 40 series, there best flowing muffler they have, into two resonator cans at the rear, then two stainless doublewalled 4" tips, also includes there own x/h-pipe.
Has a nice beefy sounding idle, low resonance at 2000rpms compared to other systems, and it screams when you get on it, sounds like an american V8 should sound. Gave a nice little kick to off midrange and high rpm pull.
My muffler shop charged me $100 to put it on and weld everything together. I used two JEG's prebent cylinder clamps to attach the back part of the tubing together, and where the catback bolts onto the stock downpipes. Surprizingly the stock pipes that come down from the exhaust manifolds look pretty good, and are 2.5" pipes also. The stock exhaust x-pipe, cut down immediately to a 2.25" pipe. I could really see how this could cause extreme turbulance, and a lot of backpressure!