Hi, I have an amplifier Marantz SR6006 and Paradigm studio surround 130w each and my center 130w. I did not as yet buy my floor stand speaker and subwoofer. My amp. is 650 Watt and the Output Power/Channel 110. 125 Watt . Output Impedence/channel is 6 ohm. 8 ohm. About how many watt speakers should I buy floorstanding and subwoofer. Please advise.