Like I said-
http://www.riflescopes.com/products/96757/aimpoint_works_568059_10174_10566.htm
That's the Aimpoint mount, ring, spacer, the whole deal. That will cowitness your sight with your irons.
http://www.bushmaster.com/shopping/handguards/hpm3.asp
Mount for A2/CAR type guards. the catalog says for rifles only, but I think it works on regular CAR guards. If not, see a couple of entries below.
http://www.bushmaster.com/shopping/handguards/fbs-fab-2.asp
Ring for your light.
http://www.bushmaster.com/shopping/accessories/sl-mount.asp
Another option to the clip on type rig, a little more stable and should fit the CAR guards.
All of this is QD, no other mods to the rifle.
From your previous post, nobody outside of .mil types needs rails and lights and such, so here is your stated desire.
Still waiting to hear what the prob with Trij is.