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