No one makes a kit for the old KLX. The bearings and seals are available through commercial bearing suppliers.
It is the steel sleeves that cause the problem. They wear and rust ! These are no longer available. If you do find a NOS set of four, then snap them up. You can always replace the bushes and bearings with a nylon insert as some have done.
There was a thread in the Kawasaki section on this subject a little while ago. See
http://forum.ozvmx.com/index.php?topic=31092.0