What would be a better idea, to buy a catback exhaust with a tuner muffler or a catback with a Flowmaster. Or should I just buy the exhaust and take it to a muffler shop and have them just put bigger pipes from the cat back. And will any of these setups compramise passing the emissions test

 

I don't think any will hurt your emissions, I would run the flowmaster just because it won't be as noticable as a stainless steel thing hanging out the back of the car, that only attracts the attention of law enforcement.