I've got Terrafirma +5.5 dampers on mine with a full Gwyn Lewis challenge suspension setup, a 2inch lift with some sort of blue springs, procomp I think, as I never fitted them I'm not sure. Its a bit "firm" on the road, but on a longer run the damping seems to soften a bit. sticks well through the corners ( for a landy on 265 special tracks :D) with only a little roll, offroad superb.
Aren't the spring ratings dependent on how much extra weight you're hauling about, winch bumpers, winches, steering guards, roll cages etc....mines dropped about 3/4 inch...but Ive probably bolted on at least 400 lbs of extra plate from when I first bought it....