I don't think they make them for this model. I have 2 bikes of this generation and always had a hard time locating one. There is a website you can check out it's called Lacomoto. These guys are from Portugal and have a lot of quality R1 carbon pieces you can purchase for your model. They do carry tank extenders but not sure if they have one for your model. If you don't see one send them an email and I'm sure they can help you locate one as their customer service is A1.

 

I found a site called monkey gripp but they're like $250 and i'm not sure if the have the spacer i'm looking to get from the tank but that's the most promising thing i've found so far.