I went with icon 2" rear springs. I have thurens 3" in the front. I have not added airbags though. With my setup I have an inch of rake and the ride is pretty good for a 3/4 ton. When I go out of town for work I usually have somewhere between 500-900lbs of tools etc in the bed. Usually closer to the 500lb mark though. If I hauled more I definitely would be looking at airbags.
My take on the icon rear springs is they ride just as good as stock if you had 500
+lbs in the bed at all times. Now with 500 lbs in the bed and the icons it rides really really nice. Tires at 50 psi or lower depending on load makes a big difference too.
Sorry I can't figure out how to tag him on here but get ahold of nick@gotexhaust he's a member on here and can get you hooked up with the thuren or icon springs for a great price.