The best rental I found in northern Italy was Motoragazzi. They have a bunch of locales near Verona around Lago di Garda.
They have their own app with day tours. You can also negotiate a multiday rental if you want to make your own tour. If you're into scenery and hot springs, the Dolomites are some of the best riding in Italy, and Garda/Verona is a good place to start. (You'll be on Monte Baldo, which is already gorgeous.) That area was Austrian until Mussolini claimed it in WWI, so it's more Brown Mountain Food™ than what you imagine when you think of eating in Italy.
As jess warned when
I embarked on my trip, transacting in Italy can easily turn into a comedy of errors (which is why he taught MV the Italian National Salute: ¯\_(ツ)_/¯). That was true in both directions, picking up and dropping off the rental.
I never did chronicle those events. In short, the people were very friendly and well-intentioned. There were a few things they were unexpectedly hard on for no clear reason (e.g. a 50% upcharge for requesting a newer model, even though they all rent for the same price for day use). Both dropoff and pickup were a little disorganized and took way longer than expected, but the staff was very nice. I ended up getting a ride to the train station on the back of an employee's small-engined scoot to catch the last train back to Venice. On the one hand, they went above and beyond to take care of me in some ways (e.g. putting a bottle of oil under the seat in case I needed a top off, or the aforementioned late night ride). On the other hand, some of the things they were so nice about taking care of wouldn't have been hard in the first place with a little more organization.
(Please, nobody quote this post. I'm in a hurry right now, and I'll probably revise my wording later. I wouldn't want to misspeak and have it live on after I edit.)