If he only wants to use it for Coyotes and other varmint shooting, go with a good scope as the others have recommended.
If he also wants to use it for Home Defense where you would need a quicker on-target time sand more forgiving eye-relief, I would go with one of the 2nd focal plane adjustables.
I have an MTAC 1x4x24, it works great for this. If I was to buy again, I would consider the Steiner PX4xi. The Steiner glass is a bit better than my MTAC.