Not KJ (they are single piston), you want WJ Calipers (twin piston) with the Akibono calipers (not Teeves). You would have to swap to WJ knuckles to run them and use WJ lower ball joints with MJ/XJ uppers.
More info here:
http://www.naxja.org/forum/showthread.php?t=1004721
95-96 XJ Dual diaphram booster/master is the most painless swap, but you can use ZJ or WJ boosters with more mods.
With the upgrades/tips mentioned above you should be ok. Just drive smart.
I was probably thinking that the KJs were also dual piston since they require 16" rims.