I've used dhl to ship bumpers to the U.S. and Europe. Shipping to Itialy would probably be around £130. I'm not 100%, it's been a while since I've shipped anything that sized overseas.
Remember to measure the bumper as if it were in a box, not just the thickness of the bumper (which is about 30cm), as couriers will not accept this when it gets to their depo and you end up with a hefty fee to get it delivered.