A friend of mine suggested them. He apparently runs them on his prerunner and was very pleased. I inquired about them for the purpose of getting 3-4" of lift without sacrifcing on road control. Apparently they custom make them per vehicle.
Here is an excerpt from the response.
"We can definitely help you with your project. We design all of our custom springs around how the customer wants them to work. We would need you to get me a front and rear axle weight for your jeep, then we computer design them and tailor them to your needs. Our custom springs are $695.00 per pair, and the bushing/u-bolt kit is $100.00 per axle. Build time is approximately 1-2 weeks. We can design the springs with the lift you are looking for, and get you a much softer ride, but still be controllable on the road."
I was more or less looking at alternative options to the kits available on the market. I'm getting ready to do a small lift, but I don't think I want to drop this kind of cash on springs right now.