Well, Aimpoint seems the way to go. For my purposes (HD, range fun, apocalypse), which Aimpoint would be best? Also, I've replaced my DD rear BUIS with a Troy DOA folding BUIS so that I don't have to co-witness unless I want to. What are the advantages/disadvantages of co-witnessing?
Hunley, you are correct. I don't have any rail space in front of my front sight and have been thinking about a Surefire G2 with a 200 lumen bulb. I've seen vertical grips that will hold the G2, but they are expensive and I'm not sure that I really want a vertical grip. Primary Arms has a G2 package that includes the G2, a 200 lumen bulb, a Gear Sector mount, and Primary Arms pressure switch for $99.