We almost went the route of Kohler/Generac, cost was insane from my perspective. Ended up with a Westinghouse WGen20000TFc instead. 125A lug for service and runs on propane/nat gas/gasoline. All in when bunker is done and all hooked up will be less than just the cost of one of the others. It will not be as quiet, but I am not planning on running outside of a need for it.