I've been running the KORE race system for about 3 years on my 2002. Is it more expensive than a "lift kit", yes. Is it worth it? In my opinion, absolutely.
Here's the process I went through before purchasing.
I live on a dirt road in a county that has bad paved roads. I also go to Baja several times a year for a week or two at a time. I knew the stock suspension wasn't going to give me the performance that I wanted. I started looking into aftermarket systems and couldn't find much at the time. I decided that I was going to have to come up with something myself. I started running the numbers and came up with the following. 4 King shocks are going to run about $400-$500 each. A new set of front coils are going to run about $400-$500. A new set of leaf springs are going to run about $700. Now I have to find some hillbilly to weld up some bracket to mount that aftermarket front shock to the tower (unknown costs). I also have to get a quick lesson on shock valving, spring rates, etc. If I screw something up, I have to fix it and I have to pay for it. I figured that I was going be spending around $3000 to do it myself and hope that I get it right. I was about to take the plung and literally, the day I was going to call and order springs, I saw an ad for KORE Suspension. I called Kent and the rest is history. I had new suspension four days later. Now, I have a truck that can outrun just about anything in the desert (except Kent, Greg, and a few of you). If you are going to use your truck off road, or on dirt roads, then it is worth every penny. There are plenty of routes you can go with suspension, but if you only want to do it once, then, personally, I think KORE is about the best way to go.