I have heard from the techs at McCormack that California power is quite variable and differences during the day/night are significant.
Should this be your case, then maybe adding a power conditioner might be something you should consider.
As far as the wiring goes, and this is only my opinion, I would have a dedicated line going from the panel to your equipment. From there, I would add whatever outlets you need to run your equipment. Stereo equipment isn't that power hungry and running extra lines for analog/digital would be overkill, again in my opinion. So, a single line should suffice which would then feed all the components. (Though if you live in a Thunderstorm or highly volatile area, I would add a whole house power protector- I am sure your electrician would be more knowledgeable. If not you could look for a high end audio dealer to give you more information.