Just a thought.
If your customer has a Win 2K network have you thought of using some kind of terminal services client to connect the Mac to the server to run the appropriate apps.
One small problem though, having just checked you will require OS X to run the free app.
Click
Here for info.
And yes I agree with Naples AC Inc. that windows Xp pro runs regularly for me until I need to install hardware or the battery runs out travelling (doh). I too would
never install any previous windows versions on my own machines, but sadly am on the lookout for an old Mac to play with you understand...