Thanks for the links, AZ.
Yeah, I guess the Lawwill bike is a good theme to base my idea on. I originally thought of it as strictly a flat-tracker since that's what it's based on, but for dirt roads it would be fine. The Supertrap high pipes look really cool and are regarded highly from a performance perspective, but I'd be worrried about burning myself and/or a passenger and they'd make mounting luggage difficult. Also need to figure out how to get more fuel capacity.