I don't know if these places will have the parts you need this time, but you might want to keep them for future reference:
http://www.desmotimes.com/http://www.yoyodyneti.com/Both are in the USA.
For OEM parts, I buy them from GP Motorcycles, the Ducati dealership in San Diego.
http://www.gpmotorcycles.comI write to them at parts a gpmotorcycles dot cm (address altered deliberately) and tell them what I need. They reply by email, telling me if they have the parts in stock. If they do, I call and pay by credit card and they ship the parts to me. The one time they didn't have what I needed, a clutch master cylinder seal kit (which Brembo quit making), they suggested an alternate solution rather than just saying "No, we don't have it." Isaac, the parts manager, is very knowledgeable and helpful.
I paid only $4.00 for shipping on my last order, so I don't think they charge more than their actual cost for shipping. It was a very lightweight order and I am in CA, but I'm in a rural area, almost 800 miles from SD. The nearest interstate highway is 150 miles away, so the cost to ship things to and from here is higher than if I were in a large city. But the roads here are excellent!
Hope this helps.