Just so you know, a KTM rotor will also fit. That should open up used part options a bit more. Have you checked into a new solid GasGas rotor? Last time I bought one the price was very good, around $80 if I remember.
I have a used solid rotor that I would like to trade for a standard vented rotor. Mine is worn and has some light groves but still has lots of life left. let me know via PM if interested. I can send pic's.