IMHO, With the efficiency of the Focal Kanta 2s, your genre preferences and your stated “85db max playback levels” (just like my setup/listening choices), the power output of the M700s will still easily allow undistorted ear-splitting 116db peaks…the M1200 might only add another 2.5 db to that!
My 2.1 system consist of stand monitors (86db), a 125W AB power amp (from 50Hz on up) and a 500W powered sub on a dedicated 20A service…dynamics, scale and resolution (attack, transients, decay) are simply Superb (of course, that is in a dedicated 90sf quasi-near-field music listening room)!
I’ve not heard the Kanta 2s, but imagine when properly set up in a balanced acoustical environment (not too dead & not too alive) and with great recordings and performances, their finesse and agility in the upper bandwidths should Easily Reproduce the sonic characteristics you desire. Personally, I’d look at your speaker cabling 1st. I just did and discovered THESE that just has taken my breath away! They present a glorious soundstage that has pinpoint focus, air and separation of vocals, instrumentals and ensembles…all in an extremely accurate and huge venue with tremendous width, depth and height…Very Musical, Realistic and Live!!
Not sure of your total power needs, but expect the P12 could be another sonic solution for system integrity. For me, the P3 (going on 250 hrs of break-in playback) fits my smaller system very well!