OK that is a big room and I suspect the M22's are not really 'working' all that well in that space, you can try to get a little more oomph out of the M22s with a close to the wall placement (1" away or so) for some boundary effect.

When you get the M60's run them at 40 or 60hz (small) and see how it sounds, then try them set to large and the sub setting to LFE + Main and then run the system the way you think sounds the best.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70