How much current?

I'm considering upgrading the power delivery to my simple 2 channel audio system. Looking for advice. Following are issues under consideration, grateful for feedback from those who have been through the experience:

1. Dedicated circuit. Willing to run a new line from the circuit box. I asked my electrician about 20A line, since all the big boys on audiogon are doing that sort of thing, and he poo-pooed the idea. Could run two lines if there is value, while he has his tools out. My current circuit has a couple recepticles and lights at the moment. I have lifted the signal ground switch to stop a buzz I think is coming from dimmer switches for the lights.

2. Wall recepticle. Seems sensible to use a quality one.

3. What about power from wall to device? It seems sensible to use a line direct from recepticle to power amp, while the other items (CD, preamp, DAC) can share a power bar. Assume a power bar with audiophile pretentions.

4. How much current for a device? At what point would it make sense to require a 20A power cord from wall to device?
Would it benefit the system if there were a 20A cord to the power bar, feeding the 3 devices mentioned above?

While I'm interested in these issues in general, my own system is fairly modest by this community's standards: Blue circle BC3 preamp, BC24 amp. Might upgrade to say, BC3000 and B28 in future, but no grandiose plans. Looking for real world advice: anyone who says a 20A line is overkill for my purposes will be personally thanked!