Martin, when you find a shipping agent for the bus, make sure to tell him that you plan to pack it full of gargo. This will affect the cost, or may not even be allowed. I have shipped a number of automobiles from the US to Europe, and they frown on any loose content inside. If you just show up at the dock with the bus full of Stuff, you may get turned away. There is also a high risk of theft.
Container shipping (for the cargo) is not as horribly expensive as one might think. They bring the container to your location to load it. Then they deliver it to your destination for unloading. You can also buy your own container if you wish to use it for storage.
But please double and triple check about cargo in the bus. It may not be allowed at all. That's something you need to find out, and soon.