It seems to me the Grand Slam 4 3/4 is underrated, but as you said it is pretty big as it has that long sloping objective bell. I have a soft spot for the old Redfield 2 3/4 Widefield and think it would provide enough magnification for what you want to do. If you succumb to peer pressure and decide on a variable, a used Leupold 1 1/2 -5 might be hard to beat.