Well, assuming the computer interface is something like USB, pretty much anything will work. I probably would just go buy the cheapest thing you can find at a place like Best Buy, because it's probably going to have a short life in a shop like that.
You could also poke around ebay and Criagslist looking for cheap used systems. I just wouldn't spend a lot of money on a system that's likely going to be subjected to a lot of abuse and neglect.
Need to buy a computer to reflash or reprogram computers in vehicles done through the internet with a special interface device.