Max - what a fabulous setup!
The DR79s are only 100 watts (stereo) into 8 ohms. We are dedicating them to bridged mono operation. Their stock power is rated at 1100 watts into 2 ohms. Hotrod will increase output. I realize that more is better, but these amps are what I have and know, and Bill T. has encouraged this particular upgrade.
My thoughts on house wire include the effects of Electrical and EMF radiation/corruption on the transmission properties of the power cable. The loads are not steady-state due to less than perfect isolation of the audio devices. Power cable commonly comes in flat and round (with a twist) configurations. I recommend the round variety with hot leads opposite. (Not star quad, but field propagation is better than flat wire when loads fluctuate.) Also consider the radiation characteristics of the outlets themselves. All 'hospital' or 'laboratory' grade devices are not created equal.
Keep us posted as you build out this room.