Hi conquistador,
:welcome: to Laptop GPS World.
The Qstarz BT-Q818X GPS receiver certainly looks like an excellent choice. But I'm not sure about *free* navigation software for Windows and Mac that would include *free* map data for the above mentioned countries in Europe. I don't think any of the programs on our laptop GPS software reviews list are free. When are you planning on traveling? Microsoft AutoRoute 2010 has been scheduled to release on November 17, 2009. It will have a free 60-day downloadable trial version. AutoRoute is a Windows application but people use it with Bootcamp or Parallels on Mac computers.
I haven't tested the following, but you could look into the free software available at
http://navit.sf.net and maps from
http://cloudmade.com (download a routable navit map). If you (or anyone else) tries this free solution, please do give us some feedback on it.