I'm not sure what kits are available now, I think most are going to air bags, should be able to pick up a set for a couple hundred bones. If you wanted to go all out you could always pick up a kelderman air ride kit.
I can tell you that my father had a set on a Ranchero GT he had back in the early 90's, rode like a brick when pumped up (was a little better with lower psi, but not much IMO). They did their job, he hauled a ton of weight in the back of that vehicle and they kept it from squatting no matter how flat the rear tires got.
On another note, I had a friend a few years back with a 4x4 CC OBS PSD that had airbags between the factory leafs and the frame on both the front and rear. They got his truck up high enough to clear 37's with plenty of room but again it rode like a horse drawn carriage on a log road.
If it was me, I would look for a bigger lift if your just looking to fit bigger tires. Your ride will be much better than a set of air shocks/bags filled to the max to get your height.