A 1-4 scope with illuminated reticule is a great optic for an AR. I have the Millet DMS 1-4. It is a great scope, and I haven't had any problems with it.
There is a tendency among new AR owners to put everything but the kitchen sink on their rifles many of the gizmos add little but weight to the gun. I encourage all new AR owners to think and rethink the purchase of any accessory.
Good luck on your build and enjoy your new gun.
edit: TAM put the wrong URL for the Millet scope here's the correct URL. http://swfa.com/Millett-1-4x24-DMS-SWFA ... 42148.aspx" onclick="window.open(this.href);return false;