some advice from a neighbour, dutchman, who is sending his bike to halifax this year. There are lots of sites, even in Germany who can help you insurance your bike. Most important thing is that it has to be insuranced before you can get it through customs. There is a lof of information on the horizon unlimited website also. But i will give you two links to insurance compagnies
motorcycle express http://motorcycleexpress.com/pages/USInsurance/
recommended by the Horizon unlimted Forum and progressive http://www.progressive.com/motorcycle/
If others here on the adv have better suggestions, please let me know, i did not insuranced my bike yet.
Have a good trip, halz und beinbruch