Yes - in my view, the North 761 amp is significantly better than the M400s. it is quite close to the 861.
If your room is large and/or you listen at medium to high volumes, I might suggest you skip the Atma Sphere monos as I can imagine them running out of steam. However, if you listen at modest volume or are in close proximity to your speakers, they might be more than enough.
But, if you can swing it, the 761 will likely be very pleasing to you - assuming you’ve heard the 861.
And, none of them will heat your room up.