I will be eventually using a 7" tft screen to display tuinerstudio via a modded netbook, it will power up when the 12v supply is activated and switch off when removed. The dash display is able to be fully customised to whatever display you want, I like this as my engine will only be low reving so a 9k reving disply would be pointless for my application. At the mo this can only be done with MS or Mtech as far as i know.

7" tft touch screen - £130.00
Netbook - £199.99
PC Technician to modify netbook to self boot when power supply is received £50 - 100

The rest is all sensors, you would need a driver i think for afr but prety much everything else is straight forward.

p.s. mapping is made much easier as the laptop is always connected. There is still a bit more research into the actual performance of this but im gonna give it a try once the cars is up and running