Best suggestion for 3.1 HT possibly using my MC402 Power Amp


Hello folks-

Sorry if this has been covered before but here's my situation. I'm retooling my Home Theater setup 3.1 and need suggestions for the following:
1. Recommendation for powered sub with a footprint of say 15" sq, priced at around $1000.
2. Receiver under $1500 and I have an MC402 amp (400 x 2) to carry the load for the towers if that's possible?
3. My speakers are the  Definitive Technology BP9040's from Magnolia Best Buy (pretty good actually)

I guess my questions boil down to sub suggestion, receiver suggestion and can I bypass the amp on the receiver and use my 402 to power the towers and center. 

Thanks 

Brent Knoll
128x128knollbrent
2.1 HT setup is:

Mc402 amp
Anthem MRX 520 AVR
Tekton Electron Mid Towers
Oppo 103 Bluray
Mac Mini with Scott Nixon Tube Dac
Aloia Cdp with Scott Nixon Tube Dac
Audience chords, interconnects
Piega Mk11 sub

The ARC from Anthem ties it all together...
Hi Matt-

The Home Theater I decided on is 2.1. I went with the Martin Logan 700w sub. Should be good enough. Thanks
Im perplexed? Receivers are all in one units amp/preamp/tuner. Why would you need one of those? Do you mean a Pre amp or Control center? Also, how are you going to drive 3 speakers with a 2 channel amp? As far as a great sub woofer I would look at a JL Audio E110.

 http://www.jlaudio.com/home-audio-powered-subwoofers-e-sub

Matt