No idea about that amp. But I can say that it would probably be worth your time to look around the DIY area for a while and look at some of the recommendations that have been given for subwoofer projects. The woofers you're considering all seem to be heavily focused towards car audio applications where cabin gain fills in an extra octave or more. In a home environment you'll be hard pressed to get any decent output at 30Hz or less (especially with the Hifonics or the Fi BTL's). And if you did try to tune them low enough to get 20-30Hz output then applying a 5000 watt amplifier would be the quickest way to turn them into paperweights. IOW, the car audio SPL approach does not translate well to other environments.
If you don't mind really big boxes, you could do this for less money:
A pair of Fi Q18's plus a QSC RMX2450 amplifier (or Behringer EP2500 if you want to save some more $)
Or perhaps you might be a candidate for an infinite baffle subwoofer.
www.infinitelybaffled.com
At any rate, I say slow down and look for some highly successful home theater subwoofer projects before spending a lot of money on something that might not satisfy.
