Unfortunately we don't have any sample works from UMPC users here at Ambient. You're correct, UMPCs use touch-screen input. Therefore, they don't have pressure support which doesn't give as good a result as say, the tabletPC you're using. In general the screen real estate tends to be somewhat less than a TabletPC due to size constraints, which is why the UMPC version has a more minimal interface.
Really neat that you have so much interest from different computer companies in your show, I hope it goes well for you!