love the bbk's on my fox, had them on a previous fox as well, and have a friend that has them on his cobra...for the price they are great.
If I had the money, Kooks all the way. If you are on a tight budget, then MAC, and then BBk. Had BBK on my 96 cobra, and had leaks.
Longtubes are decent for some midrange gains but not a great gain at peak. Sound as well.