RE: Just throwing out an idea...
SCott,
Not a place that you can shop - but definately a place you can stop. Just West of Rolla on I-44 is Ft. Leonard Wood (at St. Roberts, MO). On post, in a single building are three museums - Corps of Engineers, Chemical Corps and Military Police. Across the street from this modern, air conditioned building are several display vehicles, and a collection of restored WWII base structures (mess hall, barracks, etc., etc.).
All these things I found very interesting.
Have safe travels.
Regards,
David Doyle