Before I forget...congratulations on getting a place set up. How close to the Raisin river are you? I have a friend who's from Blissfield (just south of Adrian) and every year they have the River Raisin Festival. Maybe you could do some demo's there
If you check out this link, The Toyoda Center
you can see some pictures of their kamiza in the background. It's simple and nice looking. If I remember correctly it's two shelves with pictures and what not, a small weapons rack, and a scroll. Not super portable but by no means a permanent structure.
Good luck and congrats again.