I already posted about all of this, just try the search feature next time. Just look at threads ive started or posts ive done, its in there somewhere, btw i think the company is superstang that has the good ones, 400 bucks though.
http://www.dmhperformance.com/ecutout.htm
those are supposed to be the best, get those, and put them on, and tell us, because i am considering them too, like for the past month. (but my girlfriend doesnt want me to get them, go figure )