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
Synergistic Research will sell you a spool of their treated 10 gauge Romex at very reasonable cost -- the put it through their quantum tunneling process. I got mine via Scott Walker
You don’t want to put a 30A breaker on a 20A circuit. For a 20 amp circuit 12-2 romex would be the correct gauge to use. If you use 10 gauge it will be difficult to terminate on the outlet. BTW,12-2 has a hot a neutral and a ground. A 12-3 has two hots one neutral and a ground. 10 gauge ( 30 amp ) is used for something like a clothes dryer!
Thanks to both of you for your responses. Yogiboy-the Oyaide R1 includes a specification that it will accept 10 gauge wire. I figured-perhaps wrongly-that using the lowest gauge romex or wire possible is potentially beneficial for current draw/flow. Both my amp (ARC Ref 150SE) and preamp (ARC Ref 6) draw a lot of current and for that reason presumably only accept a 20A component-side IEC.