Hello weeksbell,
You did not say if the frame needed to be used. If not, Thorn sells a very small diamond frame that may fit. (I think it would be a little too big though). What would fit is their step through frame. They sell their frame and forks with the headset fitted. It is a very strong frame and would do much more than your tour. If you followed the build they offer you could get 16 to 99 inch gearing which is very good for loaded, mountain biking. This is their Sherpa model and is not afraid of off road use.
Tom