The Steiger kits are the way to go; factory windows and the repair kits still use the plastic corkscrew on the window mounting plate that the regulator cable goes through. Most of the time, this plastic corkscrew is what breaks, and the Steiger parts replace the whole plastic plate with a steel one. All parts and the tool needed are supplied in the box.
It all depends on what goes bad in ones KJ though, if the regulators themselves are shot then you'll have no choice but to buy new ones, then have to worry about most likely replacing the plastic plates nonetheless. They sure did overdo it with the cheap polymers on our KJs, that's for sure.
