Fh cab suspension

Has anyone ever uprated the cab suspension from the coil spring to air bags ?
The reason I ask is, I have bought one recently (used) and I think the ride is crap.
This Is partly due to my last truck being a daf super space that had air ride,anyway my shoulders are killing me,and I would have it done if it wasnt too dear.
Also I have seen a few FH 12/13s with 4 square spots set into the grill,does anyone know how they are fitted without buying a spot on integral light bar
for £450.

I agree,the steel suspension cab is a rough ride,I suffered with terrible neck and back pains when I had them.But the air cab is a lot smoother.