Romex and breaker switches


I did a search and have read previous posts, but I still have some questions. I had an electrician install dedicated lines in my listening room when we built our house 20 years ago. I bought simple hospital grade outlets from a big box store and did not specify the gauge of the romex or anything else. I need to clear out my dedicated listening room soon for new hardwood to be installed and figured now would be a good time to revisit and improve my dedicated lines. I have already bought a pair of Oyaide R1 duplexes and intend to have them installed side by side behind my equipment rack. My question is-is there a particular variation of 10 gauge romex that would be best? I have looked and there are quite a few variations including 10-2 and 10-3 and I have no idea what to buy or for that matter, if some other wire that would do the job and not be prohibitively expensive presents a better option. I will need a 20 foot run for each duplex. Also, can someone help me as to whether the breaker switch on my panel matters much and whether I should opt for 20A, 30A, or other? I now know that all runs from my duplexes to the panel should be to the same leg. I will make sure that happens. Any other recommendations or advice about romex/wire to use and breaker switches given my decision to go with Oyaide R1's would be most appreciated. 
128x128fsonicsmith
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My home is all-electric, and the two-channel stereo system is in the living room, along with various lighting fixtures, the alarm system  and leads to outdoor lighting.  I had an auxiliary circuit breaker panel installed off the main panel and had the electrician run a separate 20 amp circuit for my Bryston 4BSST2 amplifier, and a 15 amp circuit for the pre-amp, CD  spinner, DAC, Stax headphone amplifier and FM tuner. These units are plugged into one power strip to ensure polarity and eliminate hum.   BTW: You should get a licensed electrician to do the work and have a code inspector sign off; otherwise your home fire insurance might be void. 
Thanks all;
Brayeagle, are you saying you had two separate lines ran from two circuit breakers to the stereo area?  And when you say "these" units are plugged into one power strip, do you mean all the components except the amp?
Yes, two separate lines, each from a circuit breaker. The 20 amp is for the 4B amplifier, the 15 amp is for the remainder.

The power strip is plugged into the 15 amp line. 
Do not listen to what Chaz said about electrical code. He clearly doesn’t know what he is talking about- for instance, stranded wire, otherwise known as THHN, is run almost exclusively in EMT metal conduit for commercial and industrial applications in North America, which is exclusively 60Hz.  Stranded wire is used for dryer cable, stove cable, 6AWG cable for hot tubs and subpanels, and then there are service conductors. 

Also, do not listen to anyone who tells you to use 12/3 or 14/3 or any Romex or BX 3 conductor cable for common neutral and two hots on the same leg. That is a fire hazard and is against all electrical codes. Shared neutral is permitted in split phase when the hot conductors are wired to opposite legs. That is because the neutral return current is 180 degrees out of phase between the two hot conductors, which reduces loading on the neutral when both circuits are loaded with similar loads. This works best with lighting on both legs. Don’t try putting a clothes washer on one leg and your lighting on the other unless you want to replace lightbulbs every month. 

Bottom line is that you should only make changes to your electrical system if you are qualified. Otherwise, pay a licenced electrician to do the job right, and get permits for the work and have it inspected by the proper electrical safety authority.