You should check with a Kohler or Generac rep. Typically, most people around here work on one or the other, there are a few that are trained in multiple manufacturers, but they are more like small engine repair guys than electricians.
the real money in generator installs are the service contracts, not in the installation itself. If you don't want to hassle with a little bit of automotive type work twice a year, or not mechanically inclined towards engines, then you may want to look elsewhere.
I will give you the best piece of advice not found in any manual: wasps absolutely LOVE to build their nest behind the access covers. Have a can of electrical friendly wasp spray ready.
