Thanks for the input WR. I wasn't sure on which rim to use actually and mine is from a 2004 YZ250. Don't know if any big rotor options are available tho. Anyway, I got a ktm wheel for 150$ so I'll probably try that first.
Nice project btw and don't worry about the highjack (if any), I'm here to collect info/input from others first and then to show my project and encourage people to start their own. So keep the ideas coming!