Thanks for your inquiry, and congrats on your new rifle. A 16 inch barrel will limit your range a bit but 600-700 yards should be no problem. To answer your last question, Nikon over Millett all day long. The Nightforce would be a fine option in the 32mm model. Not too crazy about the wire reticle Accupoints. For the price point, Lupy Mark 4, IOR 2.5-10x42 or 4.5-14x50, Sightron SIII LR series, the upcoming Vortex Viper PSTs would all be great.
As for illumination, it's nice to have. In low lightm you may well see your target well with good glass but the reticle can be lost in the shadows. Nice to know where the bullet will go.