Lenovo Wireless Keyboard N5901
There is also this one:
Can more than one of that keyboard be used at the same time?
Most computers can use multiple input devices at the same time, the real question is why? do you want to have two people doing two differtent things on the same computer, or do you want more functionality?
It also contains scan codes a hardware examples.
Hope this helps!
How many computers are you installing in your setup? (curious)
I would bet there would be problems with using more then one keyboard in the same car, they may not work in your setup. :(
I need to read through your worklog to see how your goign to do this, I never heard of installing more than one ICE in one car. (intrested)