Dedicated Electrical

Adding another panel adds additional connections, another expensive panel, and an additional circuit breaker. The only advantage would be if the wire run is very long, 100 ft or more, in which case it would allow use of much larger gauge wire for the majority of the run with the panel located near the system. Any other situation and it is worse not better. 
 

Muliple lines runs the risk of ground loops. Even if this is avoided every wire is an antenna bringing RFI into the system. So one single dedicated line is the way to go. 
See Michael Fremer talking about his system when he says the same thing. Years ago. People are slow to adopt new information. 

I use one direct run of Romex 8/2. I found it easier to handle as it’s stranded compared to the 10 gauge solid conductors. The wire wasn’t too thick and fitted into 20amp hospital grade receptacles.

Excellent choice.

Same box is fine.

Question is which bar. There are two to chose from.

Use the one with the least major appliances-a/c, etc.

Then look at the ground and try to improve it. 

Buy some Furatech, Pangea or better receptacles.

I ran two 20 amp dedicated lines on 12/2. Seems fine.

Spent $300 on the whole deal.

Thanks guys!