I've done a little bit of night hunting mostly deer with permits. In states that's legal the Optronics scope mounted light would be a good one for varmints. Arround here it's not legal to shoot varmints at night with a center fire but I've shot a few coyotes while culling deer at night. We used a large 15 mil candle power plugged into the cig lighter and shot from the back of the truck off a bench rest. I've shot jack rabbits and coyotes in several states where legal to shoot at night. I always had someone holding the light while shooting. You haven't lived till you've shot jack rabbits at night in south Texas.
Billy