I designed this 12' (+4' porch) X 18' storage building. I had professional carpenters (beginning to feel my age) build it out of all rough-cut lumber. Then I built and hung the doors and stained it. My contractor gave me a lead on where I might find some barn door rollers. The lead panned out and I got four rollers and over 20' of track for a little over half of what just 2 rollers go for on e-bay. I will now attempt to post a pic or two.
P.S. Door rollers are antique cast iron repainted in original colors.