Although i agree with JohnK, that under most circumstances the Yammy would provide plenty enough power for general use, a recent experience has still brought me back to the old adage, "buy as much power as you can comfortably afford".
Considering your free cash available and the idea that you want a multi-channel setup, the Parasound Halo A51 might be something for you to peruse.


"Those who preach the myths of audio are ignorant of truth."