Hi,
Both those areas are nice, with many summits. If you are going for nice scenery I would absolutely recommend Rogaland (where Preikestolen is), which also has a lot more un-activated summits available. Telemark is also beautiful though, but with a very different scenery, and it can get very warm there in summer.
For track information you can check this post: Mapping resources for tourists where you can read about the services I use when hiking, and feel free to contact me if you have any specific trips in mind. It would be very nice to do a joint activation if you come here to Rogaland, I live about an hour from Preikestolen 
73 de LB4FH / Kjetil