Do you ever teach long-distance private lessons via webcam, emailing files, or anything along those lines? I've been frustrated by a few recent experiences with teachers in my area whose method or temperament didn't suit me.
This is just my opinion, but in spite of your difficulty in finding a satisfactory instructor, I still think a few one-on-one lessons are the way to go. If you live near any medium-to-large-sized city, there must be a teacher with whom you would get along. Maybe it's just a matter of looking in the right place.
Especially for working on rhythm guitar playing, as you mentioned, you need immediate feedback from the instructor---saying "No! That's not it! Stop rushing! Tap your foot, damn it!" or "Yes! That's it!"---as he watches your hands, feet, and body, and plays along with you in real time. It's hard to make that happen online.
Look for somebody who has most of these things:
-is formally educated in music with at least a year at Berklee, MI, or a university,
-is articulate and a good listener,
-has played lots of different kinds of gigs,
-is commercially published, or has some charts and/or handouts that he's accumulated for teaching purposes. This shows a commitment to teaching.
-keeps track of your lesson activities
-gives homework, especially when he sees you lack focus.
It's not really necessary that he's an astounding player, unless you're desperate for that kind of inspiration.