The general rule for flat-top AR's is extra high rings. I like Warne's myself. It seems a bit weird coming from a bolt gun, but it works just fine. Extra-high rings put your scope at the standard sight height of an AR. If you have a front sight, it generally puts the front post near the center of the scope, not always, but close. At low magnification (below 3x) you will probably see your sight, but it doesn't get in the way. At higher magnification, the scope "looks around" the front sight. You may be able to get by with high rings depending on your set up, but I've never been able to get anything shorter than that to work.
Another issue is eye relief. Most scopes will not mount forward enough with standard rings. The eyepiece of the scope should sit just above or slightly in front of the back of the charging handle, depending on your cheek weld. That's why you see so many cantilevered one-piece AR scope mounts. Check out the ones like the Burris P.E.P.R.. Leupold, Nikon, and AR Stoner all make ones similar. For a rock-solid mount check out Nightforce or American Defense.