AC POWER DISTRIBUTOR/POWER CABLE VERSUS DEDICATED

The standard 20 amp 12 gauge Romex cable is what the electrician will use.

Don't let the electrician use less than 10AWG Romex. A separate run and breaker, for each outlet. Especially if the run is better than 50'. Whatever anyone thinks or says, the difference in your system's potential dynamics will be worth it. Twisting the Romex, before the install also helps in minimizing noise.

Rockanroller,
you're in a position now where you can decide to install audiophile grade wall receptacles or let the electrician use his standard AC outlets. This is a topic of controversy due to the fact that some believe that there is no audible difference. The high-end outlets use very pure metals and are hospital grade (providing a solid connection) as opposed to the brass plated outlets.

It's not an expensive upgrade.
Check the archives for names such as Porter Ports, PS Audio.

Those upgraded outlets also are engineered to grip your
plugs, much more securely(improved conduction). Important
benefit! If the audiophile grades are out of your price
range, at least spring for some good, 20 Amp(nema 5-20R),
Hospital or Industrial Grade duplexes, ie: from Hubbell.
Note: if you opt for Hospital Grade, avoid those that
mention being, "tamper resistant." They have
extra internal contact points(less contacts=good). Music
Direct sells the PS Audio Power Port, two for
$75.00 (http://www.musicdirect.com/p-7420-ps-audio-power-port-classic.aspx)

I agree with the suggestion to run 10 gauge wire but would recommend you run 3 wire with ground BX. In the future if you decide to do isolated ground or balanced power you are all set.
Just because you run 10 gauge wire does not mean you have to use a 30 amp breaker, a 20 amp is fine as the larger wire will minimize voltage drops.