What everyone said is correct about there beinge different amp systems. However, I am thinking that there is only one replacement Kohler regulator, at least for all the late stuff. I have put it on K series with no problems. I can't remember the part number but it ends in 10. And it replaced the one ending in 09 that in my opinion was a better regulator.
The only thing to be aware of is that if the charging circuit is directly connected to the battery when the ignition switch is off the regulator ending in 10 will kill the battery in about 2 weeks. (Found this out when replacing the 09 version) Most manufacturers run the charging circuit through the ignition switch so this is not a problem.
I have installed a relay in the charging circuit so that there is no connection to the regulator until the ignition circuit is switched on to solve this problem.