Most scenig route in Sweden will be along the coast. Some of the town are worth seeing - study the guide.
When "crossing" to Norway make sure to visit Sami-culture places. A bit difficult - the accesible places like Jokkmokk are a bit out of the way (you should visit intereting Gällivare ). If you take the "direct route - the one where you cross a short distance in Finland you partly by-pass these areas.
The inland road E45 is very pretty also - but there are also hour after hour after hour of trees and trees and trees. Both routes are very, very boring due to the very many hours you pass the same type of landscapes.
The distance Stockholm-NordKapp most directly is approx 2000 km and will take at least 25 hours pure driving (no breaks whatsoever). Driving down south along N the Norwegian coast takes loger especially if you follow the small roads along the coast - in reality 3-4 days with no or a tiny bit of sightseeing.
IMHO you time will be 100 times better spend visiting some of the interesting areas of Sweden and Norway - unless your have many weeks in total.