Macs. In schools.
Where does the [censored]ry end? What exactly is "using a mac" going to teach you, except that "being hip" costs alot?
What a pathetic choice of hardware for IT lessons. I'm completely speechless. What difference does it make if all laptops nowadays are pretty much "IBM-Compatible PC's"? It's the exact same hardware with different stickers and price tag.
Hackintosh ---> Dual Boot.
If they will try to expel you, just sue them. OSX is OSX, if you really HAVE to use it, the hardware it runs on is irrelevant.
ALTERNATIVELY go a step further. Buy the cheapest Mac you can get online. Not a macbook. A Mac computer, for example a G3. Then, get a trolley, put the tower on it, along with a colourful Mac monitor and push it into the school, claiming that's your mac. Jack in and have fun TROLLing.
Mac's a Mac, isn't it?