My room is just about that size...maybe a tad bigger. I have the M22ti's and with a good subwoofer, they work really well.

The M22ti is a cleaner, crisper sounding speaker. The M3 sounds a bit deeper in the bass, and a little less crisp in the highs.

Will you have a subwoofer with these? In a room that size, you're really going to want one to fill in the lowend.