When I was buying them from oncycles a while back I tried to find out who their distributor in the states was, and it turned out to be....oncycles. I also emailed GPR at that time, and I never got a reply. Maybe translate your message into Italian (freetranslation.com) and you'll get a reply!
Yes, it does seem like Oncycles is the sole vendor of their stuff here in the states, and what they have is all on close-out.
I've already spoken with them, and it was Pedro (?) in their cust. service dept. who referred me directly to the company.
I didn't think about translating my outgoing question to GPR in italian; that's a good idea 'cause they haven't replied back yet.
The original intent of my post was to reach someone so I could get a replacement cannister hanger instead of having to fabricate something up.
The current bracket on my bike snapped at where it attaches to the subframe. Looks like I'll have to do some welding now.
As far as the questions on their quality and sound... I'll give them a thumbs up.
The welding is comparable to other brands costing more. Sound is great, nice and throaty.
I have the full titantium syst. on my cbr600rr FWIW.