You'll probably find the best solution in an avr with bass management, many 2ch receivers nor integrated amps offer such at the prices an avr can be had for altho some of the 2ch units will provide a sub pre-out but with a full range signal for your speakers and sub. The amp you linked is to power two passive speakers and a passive subwoofer; you have passive speakers but an active subwoofer and don't need an amp's output for the sub, but rather just a pre-amp's output (via a pre-out on the receiver).