I personally think I have a face for radio and a voice for writing novels, so certainly wont go volunteering myself, but I would LOVE to see this documentary made. I suggest you get in touch with Paul directly as no one deserves the spotlight this can provide as much as him - he's the one who made this forum possible and is knowledgeable in enough disparate areas to fill dozens of professional, feature-length documentaries. In fact, I'd have to say that Paul is a given - it's not a real documentary without him. Another suggestion is to talk to Ernie and Erica, the go-to rocket mass heater duo. The very epitome of creative but highly effective solutions to off-grid heating is quite literally their specialty, and they make it look easy to boot
You might want to post in the alt energy forums as well since the documentary will be focused on "off-grid" - the folks that hang around those sections of the site are loaded with good info and experiences. Good luck to you and please do keep us informed on the forum as the project comes along!