The vast majority of JK "Death Wobble" issues are track bar related. The link provided by Bone206 is excellent. If you experience DW at highway speed, it's the kinda thing that will make you want to change your undies. If you don't need a new pair, then it's a non-DW shimmy
Until your DW or shimmy issues are completely solved, I'd reccommend against doing anything to beef up your steering stabilizer. It will just mask small problems un til they turn in to big ones. Once you have the issue solved, then fill yer boots - a beefier steering stabilizer makes sense with 35's.
I'd also encourage you to see if any of the holes that the track bar bolts got through are at all "ovalized" by previous DW episodes. Make sure that you have the Jeep's full weight on the wheels when you're tightening the track bar bolts as well. Have you gone through your entire front end to check torque on everything?
I'm shocked that you've had to replace your ball joints after less than 10,000 K. I'm still on my factory ball joints (on their way out, new ones waiting for install) at 90,000K...and 40K of that has been on 35's. I don't beat my on my rig, but it's not exactly a pavement princess either.