Yes, the double breaker switchs would fit into the same space. I don't think the polarity would be effected.
Adding a second power outlet to existing one.
Just over a year ago I had installed two dedicated 20 amp runs from my main circuit box for dedicated audio use. I had each run end with two Pass and Seymour 5262A duplexes giving me a total of 4 outlets. I've been very happy with the result but have now had to reconfigure my systems location to the opposite side of the listening room. I would need very long power cables to reach equipment! so am wondering what would be best . Can I just ask my electrician to just add two more runs of cable from the same points on circuit box to a new location therefore doubling up ( although I would only ever use new location) on the two 20 amp circuits .Or would it be best ( for sound quality) even though it would take a little more work and have him remove the original wiring totally and then reinstall to the new location in living room? I have no more room in on my box for 2 new extra lines. Hope this question makes some sense! thanks in advance.