Dedicated Line

I suggest using 10/2 wire for all. Could be over kill however will not hurt anything and possibly only help.
There could be some benefits from running your electrical wiring in the following fashion:
10 gage solid THHN (white/black/green) manually (electric drill) spiral twist and snake through conduit.
I personally like to use the Porterhouse cryo'd AC outlets, which are Hubbell outlets rated for 15 or 20 amp. They are Hospital grade and deep immersion cryo treated. They are a special order un-plated version. Other outlets that have plated connectors (Nickel, Silver or Tin) that are designed to hold up in harsh chemical and / or oxygen rich environments. This is not only unnecessary for audio systems but many believe it harms the quality of sound.

I have experimented over the last several years with various wires to use for dedicated 20-amp circuits. I have the following wire in use in no special order:
1) 10 gage Romex
2) 10 gage UV
3) Belden 83802
4) Virtual Dynamics 10 gage BX Cryogenically treated with Cryo’d circuit breaker. *

To my ears on my revealing system I hear NO difference between (1-4)! I think simply using a dedicated circuit with 10 gage copper makes the biggest difference.

* There might be other positive factors to using cryogenically treated wiring besides sonics. It might lower the operating temperature of equipment.