The 8" sub in the BSW box will carry some decent tones and sounds pretty good, that's what I have but with an infinity reference sub in it. The JL uses a 10" which will have a more precise hit than the 8", which can get a bit boomy at times.
If you want the best bang for the buck there is another member who started fabricating custom boxes to fit in the same spot for $100 and you just throw a shallow mount 10" in there like the pioneer one.
Check this thread for the guy selling them for a fraction of the price of the JL box.
http://www.xoutpost.com/classifieds/...enclosure.html