I have seen a few people with Death Wobble on a TJ, and all one did was put a steering stabalizer on it. He has not had any trouble with it, and its almost been a yr now. Another buddy of mine Had Death Wobble, and the bushings in his control arms were worn out.
I have a YJ, and I got Crazy Death Wobble when I hit a bump or got going to fast, and I thought it was gonna shake my whole jeep apart before I came to a stop. Found out I had wornout bushings in my front spring packs.
May not cure your problem, but its worth looking at.