Hi Giordano,
My mother was actually born in Rome but I'm afraid my knowledge of Italian is non-existant
What I would say is that I'm afraid the screensets recently produced are all guilty of not lending themselves to another language.
To create the visual effect of the MachBlue screen for example, the buttons are all created as individual graphics. A background is created in photoshop and panels created. The buttons are then sunk into the frame.
While this method creates an improved visual, no borders etc.... It really would be a nightmare to convert to another language. (Which is a shame).
What I would say is that if your handy with a graphics program, load the individual backgrounds and manually edit the text labels. It would be time consuming, but nothing's easy and would allow for other language designs.
Buona Fortuna !