sub woofer dilemma, help


I have a pair of Alon II speakers and would like to add a sub woofer to my system. I am running off of a B&K ST202 with a B&K Pro10MC. I am looking at Velodyne models ULD-15, F1500/F1200 or FSR15. Of these, which would be the best musical match?
dvdgreco
Art of Sound or REL. Something that connects to your speaker taps will give you the best blend.
I found the Boston PV1000 to be a clone of the similar Vel, and far better than the F-series, too. Great value, and VERY fast, mating with my Spendor front trio magnificently.
The ULD-15. Next would be the FSR15. I wouldn't consider the two F-series mentioned.
Good luck!