I have a pair of Kawasaki brake discs i bought of Ebay last year as spares for my ZX9 C2- turns out they arent for my bike
They are 320mm and fit onto a kawasaki wheel fine- ( wasnt till i tried to put calliper on i found they are bigger! so caliper wont go on!!)
They are either off a ZX6 or a ZX7 or will fit a ZX9 or streetfighter etc if you use a modified calliper bracket.
Cost me £100
07973 361 713
Pics here : http://www.photobox.co.uk/album/5201043