very simple case for the 7inch touch for raspberry pi (hdmi + usb) from banggood [~40€].
it's designed for quick assemble and possible use for other displays. screws are only needed for the lid, not for the tft/lcd.
you can find the stl-files and the files for 123D-Design, so feel free to redesign for your needs!
quick and dirty with 123D-Design.. ;)