I wonder if the hardware used for this RasPi w/ 7" touchscreen would be easy enough to re-purpose.
http://engineering-diy.blogspot.com/2013/01/adding-7inch-display-with-touchscreen.htmlHe's using a
this screen which looks to be powered by 12V so that's easy. The 5V Raspberry Pi will need a bit of help potentially, but you could solve that by
throwing in one of these.