Dude....i would be very careful with that brand. I have heard a lot of bad bad stuff about those muffs. They arent much louder than stock at all, the tone isnt great, and if u dont get the ones with the corks...then they are a waste of money. The tips also look like crap. In terms of mid pipes...its up in the air man...X for more high RPM HP and an H for a more stock car to keep the TQ. u'll get a little more racey tone with an X and a lower more gurgly tone with an H. Good luck man but i would really stay away from the flowtech $hit.
Stick to the term: You pay for what you get. Flowtech is cheap stuff man, and they do have their problems. Spend the extra cash and go with a Flowmaster setup or something. I'm a performance parts retailer, and I have sold plenty of Flowtech stuff in my days. Alot of customers are happy with the Flowtech prices but end up coming back complaining about bad fit, and especially leaking exhaust especially with there headers. Since then I have tried to steer away from Flowtech. Don't cheap out man, you will regret it.
One Other thing.... Turbo mufflers are for Redneck's with Chevy Truck's Man. They are a thing of the past and really do sound like crap. Try Flowmaster, Magnaflow, Borla etc.
OK. I have Flowmasters now. They are too loud and drone too much since my heads and cam. I will look at Magnaflow. I also seem to keep going back to Edelbrock. How do they sound? Thanks.