You might want to look into the shield rms sight.It is being used by the Brits and there Commonwealth brothers in arms.It is supposed to fit the same footprint as a jpoint.It also has the advantage of replacing battery without removing from weapon.I think it might need suppressor sights to cowitness but I am not sure about that.One of those companies you were looking at to do the milling sells them and is very knowledgeable about them.