Thanks fellas,
I really just need an old junker.
Missing keys on the keyboard is ok.
Smashed or cracked screen is ok.
Dead battery's ok.

Won't be using any of those things. Once it's mounted I wouldn't be able to get at them anyway.
The PC will basically be a box that acts as an encoder / decoder for GPS and network data, and a controller for the transmitter / receiver.
As long as I can load an O/S on it and connect a few cables, it doesn't matter what shape it's in.
I've figured out how to put together (bodgey up) an automated position reporting system using stuff that I have on hand. An old computer is all I need to put it together and do some testing.
This system will allow anyone to follow our progress through the deserts on a website, in real time, by transmitting our GPS co-ordinates, velocity, altitude, and direction of travel every 5 minutes 24 hours a day.
I'm not just building it for the extra safety. It's also very cool.
