Electrical lines from fusebox to Amps--Upgrading?

I was about to use some Romex NM-B, 10 guage to make a dedicated run from my home's breaker box to the wall outlets,(PSA power ports) but thought I'd ask here about what to use to achieve an 'ultimate' result. Would using metal conduit add shielding to the system? Better wires out there? (I just heard about THHN wire ? ) And how many lines do I need? One per each amp?

Separate/additional ground? My stereo IS connected to my Video system, which runs off a Monster Cable HTS 5100, so I don't think I should isolate the ground to the stereo system (right?)

My amps are (2) McIntosh MC300's (300 w/ch). Fed by PSA II Lab cables from PSA's 20A ultimate outlets (one for each amp).

Do the front end/low power components need a separate line?

I'd appreciate any suggestions as to get the best results.

Thanks,

John