I just don't think you can beat a custom exhaust... I paid $700 for mine, so it is far cheaper than a Jap brand exhaust and is equal if not better quality. It's straight-cut so it will flow more than any off-the-shelf item (There's only a 5hp difference on my car with exhaust and no exhaust). They are made to fit your car, so I don't have issues with scraping on anything even though my car is lowered quite a lot. And it sounds way better than it does in those videos.
For me, I wouldn't buy an off-the-shelf item, custom for the win