About Ferries to Scandinavia:
Hi Firecrest, I think you'll have a great time in Sweden anyway, so perhaps it's not necessary to go all the way to Norway (Although it is SO much more dramatic and amazing).
We have done a few trips over the past couple of years so have looked into the transport options. Direct passenger Ferries to Norway AND Sweden are gone for good as far as I am aware, and the cheap flights from Ryan Air etc are the reason the ferries are no longer commercially viable to operate.
So that leaves two options..
1: Cheap flight to a local airport + car hire (tricky if you like to do comfortable camping or take your canoe etc, and car hire in Scandinavia in general, and Norway in particular is very expensive)
2: Alternative Ferry Route. This is what we did last year, it's a long drive, but we did go for a month...Ferry from Harwich - Esberg (in Denmark) you can now drive via Copenhagen and over the bridge up to Gothenburg. But what we did and was actually a great part of the holiday, was to drive up through Denmark to the very Northern tip, which is basically a long sandy spit called Skagen, camped one night there, then there's a ferry from Fredrikshavn to Gothenburg which takes about 2.5hrs. Driving from Gothenburg to the Norwegian border takes about 3hrs, and to get up into the really interesting stuff takes about 6 - 10hrs. (I know it's a long way!)
Small bit of good news... there ARE still commercial i.e freight / truck ferries to Sweden (Gothenburg), on which you are allowed to travel as a passenger, and take your car. They are fairly basic, and take ages to get there but maybe it's an option. Bad news is they sound like they should be dirt cheap, but actually aren't. Have a look at...
http://www.dfdstorline.com/DfdsTorLine/EN/Presentation/Passengers/index.htm
Hope this was some help.