I'm currently enjoying a coffee break at the office and stealing some internet time...
...can't get Beyond security filters and see motorcycle rental rates in Rome...
I'll see if I can get it done tonight, in order to give you an idea of rental costs
(I do not recommend crating and shipping your bikes across the ocean...
unless you intend to ride all the way across Europe for a month or two... or three !!!)
Anyway, other than plain "scooters" with CVT transmission... you can rent BMWs and Ducatis...
Expect to pay around $1000/week for a BMW F800GS (800cc twin with 80hp) or a Ducati Scrambler (800cc twin with 80hp)
...plus gas at $ 6.50/7.00 / gal...
Still... methinks a week in Italy (or two) is definitely worth it !!!