Home Theater Processor

I don’t think the M17 does Atmos. 

Of the two the OP selected, the MX160 has roomperfect, which is the best option for room correction. 

But I would recommend waiting. Next gen pre/pros with hdmi 2.0b or even 2.1 are almost here, and 4k with dynamic HDR should be good enough for most people for the next 10 years, like 1080p has been. 

The Classe sigma SSP mk2 does atmos, but you could also look at the Marantz 8802. 

The Mcintosh MX122 is also an option. It’s the baby brother of the Mx160. 

Keep an eye on the HDMI version of the units you buy.  Without at least 2.0a, you can’t get HDR, which is probably more important than 4k at this point.