The reason I suggested M60's for stereo listening is sometimes I find listening to stereo music with a sub distracting. A subwoofer is usually placed in the corner or on the side of a room. You are not supposed to be able to tell where the low frequencies are coming from - but this is not always the case. I can tell the bass is not coming from the center of the soundstage - so I like to listen to music just with two full range speakers. This may just be me or my set-up.
I did not notice the size of your listening area was 13x13. Three m22's across the front may be the best choice. That would really be a seamless soundstage. As far as the center channel goes, I would look for a stand that will elevate the speaker as high as you can get it without getting in front of the screen. Ideally, you want all of the tweeters to be at the same height across the front. Of couse this is hard to do - you just try to get it as close as you can.
