Just a word on the disk rotors you often see on ebay etc.
The standard (non-ABS) rear disk is a 7mm thick unit with 6mm minimum:
The fronts are 5mm disks with 4.5mm minimum. The Metalgear web site also draws ones attention that some front disks are 6mm and then identify their part number for the thicker units.
When I check ebay sites I notice that the disks offered can be quite a bit thinner.
For instance a ST1100 rear can be sold brand new as a 5mm disk. Thats a full mill less than the 6mm minimum.
Please check the disks thickness before making a purchase.