Onkyo TX-SR606 -Klipsch (2) f-2 towers -Klipsch Quintet SL Surround sys (5 spkr sys) Not using the center channel. -Polk Audio C20 Center channel HDMI only, all the way around... PS3 HD satellite receiver running to 46" samsung LCD 1080p television room is approx 21' x 24' with 10' ceiling... Watch mostly movies not much on music.. I have a few subs in mind such as Yamaha YST-SW515 Klipsch KSW-12 Klipsch RW-10D Cadence CSX-12 Polk Audio PSW505 Polk Audio PSW125 Practically speaking, if they were all the same price and for the system i had with the room I'm using. Which one if any would be best???