I have 5" skyjacker coils on my 2nd gen. I dont think they even squated an 1" with my 6. 5' Meyer Aggressor E-68 plow. With my stock coils, it would squat a good 2" or more at least.
To be honest, having a lift and a plow frankly sucks. You cant see anything at all, behind or infront of you. The plow will be at the wrong angle, unless you have the mount adjusted to accomidate for the lift, then it just looks dumb, because your bracket hangs way low. Maybe a 2-3" lift would be better, but with 4+ inches, I think its a pain. Luckly I only use it to clear my driveway, and occasionally a brothers driveway. I would go nuts if I did it as a job with a lifted truck.