Yes, I have rented a Vespa in the town of Olbia in Sardinia and had a great time. The contact is Maura at:
My overall experience was extremely positive; the bike was great, and there are many beautiful roads to explore.
You probably know this already, but just in case -- in order to rent a bike of 150cc or more, you will need an International Driving License endorsed for motorcycles. You can get this from RACV or other providers.