You could take it with you if you used your own funds. The school would not be obligated to provide any kind of support for it. I'm surprised they aren't buying them
I use the Smoothboard wii do it yourself interactive whiteboard. We made it as a class project and I love it. It is portable so I can move it from classroom to classroom and it is almost as good as the SmartBoard that I have in my morning classroom. I would suggest that you look into this first. I keep my computer and projector on a cart and attach my Wiimote to the cart with a clip-on tripod. This way if it moves, I do not lose calibration.