John Fahey is an outstanding musician and I would second that recommendation, although you should keep in mind that he travelled ALL over the map musically. Some of his more recent projects bordered on musique-concrete even. Do a little research on his discography first, but definitely dig in to it. It was, I think, Rhino that put out an excellent two-disc anthology which would be a great starting point. If you like Fahey you could even travel a little farther out on the limb by checking out Robbie Basho, another cohort of the Fahey/Kottke camp. A few other musicians that come to mind who may fit loosely within the genre(s) that Kottke resides in are Sandy Bull, Davy Graham, and Wizz Jones.
Any others like L. Kottke Clone CD?
Wow. Just picked this CD up at the local Tower store and it is incredible. Are their other artists or recordings similiar to this with outstanding music and sonics?