SørenH wrote:
We are heading for the inland waterways of europe, the first year
Germany, Holland, Belgium and maybe France.

You will not find a single best provider for the whole of Europe and
interconnect charges are excessively high. The EC did have to regulate
to cap the most excessive rates, but you still want to use a national
provider in each country.
There are competitive offerings, but you might want to change operator
when you change country. As you'll stay a while in the same country this
should not be a big problem, though.

For example here an offering (Germany) for a 25Euro flat rate for
internet usage:
http://www.handys-mobile.de/base-internet-flatrate.html

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