I run a Primary Arms 1X6 on one of my AR builds. One thing to remember is that most of these magnified scopes do not come with a mount so you are looking at add $50 to $200 for a mount. Don't skimp on the mount.
If you are mainly going to be bench shooting and the gun will not be used in a tactical role I would go with a fixed mount without throw levers because it will save you $$. If it will have a tactical use get throw levers so you can take the sight off in the field.