There is the Isoclean Zero Ohm breaker panel, but I’m not sure if they make it anymore since it’s not listed in their current products (used pure copper elements and gold plating). At $5k, I don’t think it’s in your budget, since balanced power is not. I have seen some panels that have a built-in isolation transformer, but I can’t remember the brands.
Like Eric said, Siemens or SquareD. In my case, I went with SquareD because it was available locally. Use 20 amp breakers instead of 15 amp. Run as many circuits as you want. Use a single run of Romex per outlet. You can have two runs of Romex connect to one breaker (but check local code on this).
You can get cryo treated Romex here:
I’ve used this vendor many times and he is excellent. Even though he’s Canada location, he ships via USPS Priority from New York to anyone in USA. Prices are in CAN (just multiply his price by .77 and you get USD - for today’s exchange rate).
I have noticed a difference in sound between the awg of the Romex. A 10 awg Romex can carry a lot of current and is great for amplifiers. However, source/preamp equipement is more sensitive to the awg and will blare somewhat (push to hard) with larger gauge romex. Amplifiers are much less sensitive to this. Using a 12awg Romex for source/dac/preamp is probably better. I actually use a double-run of 14awg Romex for my preamp outlet (essentially a 11awg run).
Of course, choose good quality outlets. I recommend Furutech FPX Cu (unplated copper) as a minimum. It’s a good neutral sound that is fairly inexpensive You can go with gold-plated if you want a warmer/softer sound or rhodium plated if you want the detail/punch/resolution.