I am also after some ball joint rubbers. I have looked into this and the only way to get the exact fiat ones is to buy a new arm which btw costs the same as the ball joint rubber set posted above. However, get down your local car shop as long as its not halfrauds with the rubber you need and they should be able to give you a pretty close match immediatly. Im going down my local A1 motor store at the weekend.
Cheers
Rich