Genset Service

I do most of my service and repairs.  However, I am looking for some backup for those projects that are not getting done.  The Onan 9kw diesel genset needs service and I have been too busy. Looking for a top grade recommendation. I admit it- I am a pick customer. Having said that most service providers like working for me since I really understand the time and issues accociated with top notch service. Previously used Cummins NW and was happy, but they relocated and charge $475 trip fee for the drive. Plus my main guy got promoted and only turns wrenches on train engines. Will not go back to S3. Any experienced mechanics out there use someone they trust?