From what I know and what I think that I know, I believe I would recomend the M3s for this application. The M3s have the same bass as the M22s but since the M3s have a very slight bass hump, they "sound" as though there is more bass. They may be even be a bit more pleasant sounding in a more reflective invironment as well. The need for a sub won't be near as pressing with the M3s either. Also, since they are shorter and lighter, the M3s may even be easier to wall mount!
They won't, of course sound exactly like the M80s, but there will be a strong Family Resemblence. Though with more of a laid-back feel. They won't give you the accuracy of the M22s or M80s, but since the speakers won't be used primarilly for serious listening, this may not be a significant problem.
The M22s "sound" more like the M80s but with much less bass.
The M3s are a little closer to the M80s in bass but don't have the accuracy the M80s are noted for in the midrange.
Add a sub to M22s and you sort of have.....
