I tried out m22's and m60's (my living room is similar in size to yours). Originally I planned on running only a pair of main speakers, without a sub. There was no contest: the m60's have the mid-range clarity of the m22's, but with much added bass - and no stands required. I've been using m60's for almost a year by themselves; I find they do a great job with all genres of music, and acquit themselves pretty nicely for movie playback. I could and would live quite happily with this arrangement.
Unfortunately, I love the sound of the m60's so much, I couldn't resist filling them out to an Epic 60 5.1 surround system; the other speakers are now on order from the factory outlet. Don't make the same mistake I did - run to BestBuy while you can, get an insanely good deal on some crappy speakers, and pretend that they sound really good. You'll be impressed with how much money you can save. If you let yourself get hooked on the Axiom sound, it's just a downward spiral...
