Best powered Subwoofer for HT only... Under 1000

I need a subwoofer for my HT system. It will never be used for music, just movies. Besides keeping the price below $1000, the height of the unit cannot exceed 16 inches since it will go into a cabinet below the viewing screen. I have read great things about the Hsu VTF-2 which is only $500.00 (and 16 inches tall). Is there anything else I should be looking at?
Thanks, Ken