I seriously don't think any 7" monitor will fit in the oval while leaving the climate controls where they are. Not enough room for the controls anyway. I don't know if you have seen "Starship"'s ZX2. The one with the removable rocket pod on the trunk deck? He has a real custom dash. For other possible ideas:
http://www.cardomain.com/id/starship
If you plan on not using your donut spare in the trunk, you could make a more solid/stable platform for your computer case to stand on. In my case (pun not intended), the case was too big and I did keep my spare. Not to mention that the fiberboard cover is flimsy. And the Mini/Micro ATX case was just too big to fit in the back, that's why I got a SFF computer now.
Have you checked my updated pics on TeamZX2.com??? I have posted some there as well as in the "show off you project" forum here.