Holy heck that is some serious coin for shipping. If the truck you bought was small enough to fit in a sea container you might be able to get a better rate. I know that's what some of the Mog importers do when bringing stuff in from Europe. They get a flat rate per container. There is also drive on drive off shipping, but that would require you to buy a running truck from GL. Course, the drive on stuff sometimes ends up on the deck and that can get interesting in a storm. Not that containers are any safer being that there is often not a lot of concern given to contents when loading and unloading. It would be very helpful if you could make contact with a shipping agent in Guam that would ensure that everything gets done right.
It's all a bit too risky for me personally.