Sources for information and/or advice on dedicated AC lines desired

I’m also in Portland OR and just gone through build out of my room (details in my system description)

i think you have most of it but please consider one line for each channel so you can support monoblocks later on. Personally I still use my SR Powecells so only actually use two of my five lines but never hurts to have them.

I also installed a Torus WM 75 transformer to isolate the system from the rest of the house, not cheap but very effective. There are also other tricks like using an Environmental Protections EP 2775 ground filter to help isolate from ground noise, again details in my system description

unfortunately the hi if dealers her in Portland are not what you are used to in LA, I still do most of my business with the folks I used to work with, but Jonathan Tinn at Chambers Audio has some excellent lines and very good service. Send me a private email if you’d like to check out the system some time and see how I approached the issues you have. I may also be able to recommend an electrician you could use

BDP- I don't think a separate subpanel in itself offers better isolation, but where it is attached to the service line relative to the other breakers might- you need someone with better electrical chops than me;
Contrary to my earlier advice about a million separate dedicated lines, there are benefits to keeping (at least the analog stuff) on the same line if possible, to minimize the differences in grounding potential among different dedicated lines; downside, apart from current demand issues, is running a separate "distribution box" ( high quality "power strip" ala the UK style of wiring hi-fi) power with at least one more, and several longer "audiophile power cords" that, together, can be pricier than electrician wired in wall dedicated lines;
the isolation transformer is a great way to minimize electrical system crap, particularly in combination with a dedicated line; these transformers hum so where you locate it relative to your listening area is important.
good luck, have fun- these kinds of projects are pretty satisfying in the sense that you accomplish something without just buying "gear" and the improvements are well worth the investment in my estimation, even on a relatively modest level (The electrical work I had done in NY wasn't that involved or costly, and I was dealing with finished walls, not open framing in an area of the house most distant from the basement/service entrance). 

Hey BDP...again, good luck to you. You certainly got a good number of tips from the members to at least consider.

I wanted to mention PorterPorts as another option for your outlets. I can’t swear these so-called "audiophile" grade outlets make a big difference to the sound vs a cheaper builder’s grade outlet (I never did any A/B testing)...but, neither the Cabledynes or the PorterPorts (i.e., cryo’d outlets from Albert Porter, A’gon member) are that expensive and I’m not an extravagant spender. Anyway, might as well go for something like them given this opportunity you have.

For me, in the lessons learned category...
I have a very modest APC H-10 power conditioner on the middle line. Sources (e.g., CDP, DAC, TT & phono-pre) are plugged into this. Amp (power & pre) go direct to wall outlet(s). During winter, when the heat pump kicks on - even though it’s on the main panel and not on the sub panel for the dedicated lines - there’s enough (momentary voltage drop from the furnace power draw?) that I can hear the APC click on and respond as it is designed to do. I don’t hear any change in the music; the APC intervention is VERY brief...but this is why, if we had the budget and time, I would love to have installed another line from the street to a completely separate panel (not just a sub panel) to power the audio gear. Maybe Whart’s & Folkfreak’s transformer suggestions would fix this without a 2nd line going to the house. Dunno.

If you wanted to spend some big dollars on outlets I'd recommend the following:
Furutech GTX-D Rhodium (R)
Or the new Synergistic Research BLACK UEF Duplex receptacle.

@bdp24 for what it’s worth, I recently completed a similar project. My electrician installed a 20A circuit breaker/line at the bottom of the panel far away from large appliances and anything on a dimmer.

All existing wires and cables exit through the top of the breaker box. For the dedicated line he exited directly through the side of the box with Southwire Romex 10-2 wire.

He kept the wire run completely isolated. The run enters a junction box and two Southwire Romex 10-2 wires then make their way into two Furutech GTX-D (R) wall receptacles.

I have an amp and phono pre occupying the two outlets on the left receptacle and my turntable occupying one outlet on the right receptacle.

Regarding grounding, nothing additional was installed or done. The electrician grounded the line with the existing house ground.

there is a noticeable difference in noise floor, dynamics and less line level noise. These particular outlets take quite a while to break in. Some suggest 600-800 hours.

good luck with your planning/install.