Nice stick, Scott!
The set up you have going looks like it should be great, a couple of comments.
-You'r RSA, make sure you really check it out mounted on the bottom rail. Most of the times you find them mounted either on the side rail with the ring facing up or on the top rail. I would just be worried about the gun wanting to roll when slung because both of the sling mount points are so low. But if that setting works for you just run with it, totally personal.
-For a light, take a look at the new surefire mini scout light(M300B). It's a 200 lumen single cell light that's nice and streamlined. The X300 Ultra makes another good option, or the Surefire Fury in a light mount makes for a little bit less expensive set up. I wouldn't recommend lights that have a high and low mode, to much of a chance of the low mode coming on when you really need the output.