Hello, I have a living room setup with 4 Rf-800 , 2 Rf 820 , 2 buysurround klipsch( next to be upgraded) , 1 RP 504- C and 2 RP -1200sw. I am driving all but the Subs with an onkyo TX-NR 787. The system sounds great at full volume can't even get a whisper of distortion. Which leads me to feel I need more power for all of this. Can anyone suggest or share what kind and brand of extra amplification are best suited. Thank you kindly1