Revic BR4 if you’re looking to buy once cry once and want ballistic solutions.
Should always carry a spare battery, but if you go with Sig probably two. My Sig didn’t have the common battery drain issue but it only consistently ranged to 1/4 the rated distance (1600, I’d expect 800 in good conditions, only able to consistently get 400. Occasionally it would figure itself out and range out to 600).