I have some youtube videos from my install the other weekend in the WK2 performance intake and exhaust section if you need some feedback on interior sound levels, etc.
As for which way you should go, it makes no difference Corsa vs. Mopar since they are the same system as others have pointed out. What you will find though is that you can shop around for the Corsa system and knock $400 or more off the direct cost of the system, and if you install yourself you'll save even more. 6 hours to install the system is RIDICULOUS and outright ROBBERY. It took me 30 minutes to get the stock system off, and if I had a lift and another person it probably would have been more like 15. It took me about 2 hours to install the corsa system, but again, drop that time significantly if you have help (I did it all myself with the help of jack stands) and/or a lift. I just used the Quadra Lift to raise mine and used jack stands as well as my knees to hold things in place while I tightened the system down.
Is it worth the extra $ to not have to deal with the Mrs? Only you know the answer to that!