Ok, I have taken some photos so you can see what i hope to achieve. As you can see the air conditioning vents are a good place to mount the rear screen. At 7 inches the screen will fit like in the composite picture, but if i put a 9 inch it would cut out the switches to either side of the vents. This is not a big issue as they are 'set and forget' anyway.
I suppose the next thing to do is to decide what hardware i need to make this setup work. So does anyone have any ideas? I will need a motherboard which has dual monitor support (either 1x VGA + 1x TV or 2x VGA). Can anyone let me know of one which does this?