I have shipped a couple of bikes to Poland from the US. One of them was to another RRB forum member...tuinam is his user ID.
I used a shipping company that was located in Chicago Illinois in the US. I can't remember the name,but they are a Polish company and specialize in shipping to Poland from the US.
The way it ended up being the cheapest was for me to box up the bike and ship it to the company in Chicago via Fedex. I labeled it with the address in Poland and they shipped it from Chicago to Poland. I handled the shipping to Chicago and then the person who was in Poland handled the rest.
I think it was about $75 US to ship it from Chicago to Warsaw Poland and about $50 to ship it from me to Chicago.
Here is a link to a company that does the same sort of thing. (Not the one I used though)
http://polonez.info/
I have a few projects that might work for you..Send me a PM and I can send some pics