Cris
I assume you've tried the obvious - a Ducati dealer? Failing that, have a look at the Dzus web site (
http://www.southco.com/landingpages/dzus/).
If you need someone to recover the seat pad, I can recommend RD Designs, 2Milne Walk, Hartlepool, TS25 3RQ. They did an excellent (and quick) job on mine when I wanted a thinner one made up.
HTH
Andrew