3 points are basically obsolete at this point, for your intended purposes based on your post I'd go with a 2-point. If you are doing alot of tactical shooting then a one point would be best but I think you'll enjoy a good 2-point better. I use the mag-pul MS2 on one of my AR's and it can be switched from 2 point to single in secs. It is a bit expensive though. For a good 2-point look at Vickers slings, considered the best 2-pointers by many. Also the VTAC is good for a bit less.
http://www.bravocompanyusa.com/Tacti...ounts-s/22.htm