The M50's are a great speaker, don't worry about them being too loud or too soft for your room. That's what the volume control is for.

As for the amp required. Isn't that denon 110 wpc? That's more than enough unless you like to listen VERY loud. I'm using a 1602 (70 wpc) to power M3's, and soon to power M22's and VP100. My dad's technics from the 70's at 25 wpc powered the M3's no problem, as well.