AC POWER DISTRIBUTOR/POWER CABLE VERSUS DEDICATED

Both! Any current draw on a shared circuit, will cause a voltage drop, to one degree or another. The smaller the wire gauge and/or higher the current draw, the greater the voltage drop. Some noise from other devices, can still be transmitted through your panel's neutral and ground buss bar, which are shared by all branches. A dedicated circuit will help with the first issue, a good power purifier or regenerator, the second. Personally- installing a twisted, double run of 10 AWG Romex, to my listening room's outlets made a dramatic improvement. Already had my Stealth XXX.

A dedicated 20 amp (2400 watts) circuit is more than enough for
anything you would ever use. A 30 amp outlet is for a clothes
dryer or hot water heater with a different type of plug that no
component cord would even fit . So yes ,you are better off
spending the money on a dedicated circuit than a power
distributor !

Great. I will have the electrician install two 20 amp dedicated circuit lines .
Second part of the question: does the electric cables , as well as the connection to the breaker box and the wall plug have to be a certain kind or models ?
Also, can someone clarify on the fact of having a power conditioner for the whole house installed?
Thank you kindly for all your answers.

Any licensed electrician will know what to install. Are you sure you're not doing this yourself ? If you are, be careful you don't burn your house down!

10-09-15: Yogiboy
A dedicated 20 amp (2400 watts) circuit is more than enough for
anything you would ever use ... One amp = 120 watts,so you can do the math and
you will see that you will never need any more than that.

Oh no, this is completely mistaken. That's because no amplifier is 100% efficient. Look at a Bryston 4B amp, for example. This nominally a 300W/channel amp, but it draws 2100 watts of AC when driven hard at 4 ohms. So if you're running high-power amps, you'll want a 20A dedicated line for each, plus at least one more line for your source components.