...I think all the stuff you listed will probly work out OK, and once you start fooling aroiund with a gearing calculator, you'll quickly realize whether you need to buy another, wider range cogset for the rear to amplify your range.
My only observation is that if I were going to the trouble of building wheels for a loaded touring bike that I planned to use for long rides out of town and into remote areas, I would not build them on 32 spoke hubs. I would go to the trouble of obtaining hubs drilled for at least 36 spokes.