Inox Fasteners are very helpful & quick. If you get confused about sizing/threads etc just send him an old one & he'll match it. www.inoxfasteners.co.uk.
Please note uncle porry, that normal sized bolts will catch on the speedo drive, so make sure that you get ones with a lower bolt head hight. genuine Ducati Disc Bolts are only £19.?? ( can not remember the pennies amount) for a full set for both front discs.