Unfortunately the best Iron sights, Tech Sights, available mount to the standard receiver scope mount holes.
This is the reason I am building my Dlask build with a standard receiver. Tech sights makes an adapter that will fit on the bull barrel that has a dovetail for the front sight, but that rear receiver makes things impossible.
You will have to look at barrel mounted options, and have dovetails cut into the barrel or have it drilled and tapped to mount the sights.
I would probably consider selling the Dlask receiver, and going back to the original, and then going with the Tech Sights. The Dlask receiver is useless if you aren't scoping the gun anyways.