Selecting from your list (since you have already narrowed down your choices to 3), and you will be adding a sub sometime in the future, i would go with the M22s.
The M60s are overkill for a room that size and the M22s are nearly identical in overall sound, kind of like the little version of the M60 (but they really are not as small as many think).
When coupled with a good subwoofer in the future, they will really shine.
If you are leaning towards towers, then the M40s is also a good choice. They are often described as a bit more laid back in the upper frequencies compared to the M22/M60/M80 models. But there is just something about having a tower speaker that adds to the largeness of the sound that i find appealing.
