I´ve taken that ferry from Bergen/Stavanger to Newcastle and v.v., but unfortunately it hasn´t operated for a couple of years now. Nowadays a lot harder to get across between Norway and UK. Check out ferrylines.com: Europe's Ferry Booking Portal to get some idea of possible routes.

If I were you, I´d consider riding Norway´s coast to the north, and then head east to Sweden and Finland (you´ll be able to do it overland from the north side of the Gulf of Bothnia, or you can take a ferry from Umea to Vaasa). Norwegian coastline is definitely one of the biggest highlights of Scandinavia, plus in my view, both Sweden and Finland are more interesting in the north, not so much in the south.

Do also take note, that it is VERY slow-going near the Norwegian coast, and your experience will greatly depend on the weather. It does rain (a lot!) especially near Bergen. And it´ll be a good idea to obey the speed limits, as fines are astronomical in Norway. More or less the same goes for all of Scandinavia, though.

Timing your trip to Scandinavia is also one important thing... the summer is very short here, I´d say that the best time is starting right about now (end of June until around the end of August). Still the weather is not guaranteed, and it can be fine one year, and more or less terrible the next.

If you´re planning to do your first tour outside that mentioned period, then I´d probably head to southern parts of Europe first, as it´ll probably be a lot warmer. Or if you decide to do Scandinavia, make sure your rain-gear and camping-gear are up to it.

On the other hand, I just returned home from a trip to Sicily today, and we ended up skipping Eastern Europe both ways, ´cos it has been raining more or less non-stop in certain areas for over a month now....