For Starters, you will want to create a grouping for these computers either using a smart computer group or a static group, whichever makes most since in your environment.
I'm not sure about the script for turning off Ethernet, but there is a script in the resource kit to turn off the airport. It is called "disableAirPort.sh" I'm not sure which OS this will run on, so testing will be needed.
Of course, getting a script to turn off ethernet is the next portion. Of course, you will probably need a way to reverse these and that may get more interesting. The airport script is easily reversible from what i have read in the scripts own documentation
