Dedicated lines — how many? Other advice?

It’s probably not much more expensive to run two dedicated lines than one, so I’d run one for analog and one for digital for the dedicated audio only. I wouldn’t bother with the A/V stuff — just get a good power conditioner with surge protection with power regulation to protect/prolong their less-robust power supplies and electronics.  FWIW.

Use one direct (dedicated) line for the audio. This will be your high end system line. Everything connected to this system must be plugged into this circuit. Nothing else. This is to a) provide the best power and b) avoid ground loop hum and other noise problems.  

Everything else can be on as many circuits wired however you want. I would recommend one circuit for lights, one for all other outlets, and plug all the other stuff (video, etc) into those other outlets. 

Do not use more than one line for the audio. Use one power conditioner and plug everything into that one AC source. Does not matter how you group components. (There is a lot of misinformation around all these topics. Study my system. See who has what experience. Nuff said.) 

Skip the surge suppressor. Waste of money.  Spend it where it will do more good. Get the Decware Zen https://www.decware.com/newsite/ZLC.html

Use 10awg wire, 20A, and do not stress the details. For what you can spend on stuff you will never hear you can buy one fuse that will make a hundred times more difference. I know. I have wired my room several different ways and heard what all these different things actually do. There is more benefit to a good AC outlet for less money and work than what you can do paying an electrician, trying to convince him, etc.   

Try and keep some perspective. The single biggest improvement by far is to run the one line direct. Otherwise, electricians will always wire a circuit to go from outlet to outlet in a daisy chain of connections. Eliminating all these connections is by far the biggest gain. I have wired my room at least three different ways, including ripping it all out and having all the wire cryogenically treated. By far the biggest improvement was that first step of running the line direct. So do what you want but realize there are things that are extremely cost effective, and then there is a lot of other stuff that you could do way better with the same money any of a dozen other ways. 

Thank you for the advice so far. Since the entire room is being wired I do not think it will cost anything much more to run more than one dedicated line if that seems best. I see arguments for and against that so far but cost is not going to be a factor I don’t think so I could run more than one or just one whatever is most advantageous to the sonic outcomes.

on another thread much earlier in the year or, last year, at least a half dozen people recommended getting a whole house suppressor to protect gear, not just for the audio system, but for protection elsewhere in the house. But you are saying skip it, MIller?

Run at least two dedicated 20 amp lines, you can always Revert back to one line if you think it sounds better. I have 6 in my dedicated audio room, and I don't have any ground loops.

How many lines again, Michael? https://youtu.be/H07NpWk_Xf8?t=947

Surge suppressors? Almost everything electrical it is low voltage that causes problems not high. All my sensitive electronics from computers to CPAP run right off 240 when I travel just fine. The reason is they all have power supplies. The first thing that happens in a power supply the voltage goes through a transformer that steps it up or down to whatever the device requires. It then goes through diode rectifiers that convert AC to DC, which is stored in power supply caps. Voltage surges do nothing but help the caps charge faster.

That's if the voltage surge is from say 120V to 240V, which is a pretty big surge, but nothing can't be handled fine anyway. So surge suppressor no good.

What if you are hit by lightning? Then the surge can be 60kV, 100kV, the skies the limit. This kind of voltage takes out your roof or wherever it hits, and arcs right through your circuits in a surge so big and fast only seriously designed protection is gonna do any good- and maybe not even then. Go look at what a direct hit can do.

People buy these because it makes them feel so good to imagine they are maybe gonna be safe from something that in all likelihood never will happen, and are willing to pretend this all comes at no cost in terms of sound quality.

We spend thousands and go to great lengths to run a direct line to eliminate extra connections and the noise they introduce, then turn around and believe none of that matters any more because, "surge suppressor". 

But fear will cause people to do all kinds of things. Remember your Dune: "Fear is the mind-killer."