Sweden’s most alpine areas are Sarek and the Kebnekaise area. Here´s a few pics from Sarek so you can get an impression:




There other less wild areas in the mountain range still above the timberline that can look like this:

This is still quite nice. You can choose your path more freely and it’s a wonderful sense of openness and freedom on a day with clear skies. (Yes, it´s my dog.)
The birch forest closest to the timberline is also really nice:

We also have a lot of places of lower altitude with forest and a lot of lakes (it´s supposed to be 400 000 lakes in Swden) .
I can’t help you as much with Norway, but remember it’s still worthwile…
The most well-known trail is the Kings Trail that stretches 425 km (264 miles). I try to avoid it as much as possible, so I have only done a few shorter sections. It´s where you find most people and it tends to become quite worn and wide in many places. It is however well supported with huts by Svenska Turistföreningen (The Swedish Tourist Association)
There is more of a network of trails/paths generally in the moutanis, and I think one of the pleasures is to pick your route more freely from the map in this vast landscape with very few signs of civilization. Why do you always have to follow a trail? It is not uncommon to meet people from countries like Switzerland that come for this reason.
It’s not that hostile in our mountains. If you are an experienced hiker it should not be a problem. The main thing to be prepared for is several days of wet cold weather. This is manageable, but it can lessen your experience. However, the only alternative is to don’t go at all. There can also be a lot of mosquitos and no-see-um’s but that is also manageable and a bit better above the timberline. But if you haven’t brought the means needed to protect yourself it is unbearable, in the true meaning of the word.
This site by Jörgen Johansson may help regarding what you need to bring:
http://www.fjaderlatt.se/
Jörgen has developed his skills and gear choices in this environment so it will work up in the Swedish (and Norwegian) mountains. His book “Smarter Backpacking” is available on Amazon, a good read before coming here the first time.
http://www.fjaderlatt.se/
If you want a device for help in an emergency (recommended if you are alone) the Spot is unreliable in Laponia because it uses geostationary satellites that are to low on the horizon up north. A PLB works and In-Reach should also be OK I understand.
This could also be interesting:
http://www.swedishtouristassociation.com
Otherwise the forums I tend to use are in Swedish so they would not be of much help.
A few more words on the most alpine areas, Sarek and Kebnekaise. The hiking season for both is typically mid-July to mid September. The Kebnekaise area is well supported with trails, bridges where its needed and huts (Svenska Turistföreningen) were you can cook, sleep and resupply.
Sarek is called “Europes last wilderness”, there is more or less nothing except for two bridges. (But you will meet people, especially at some places. You can however also choose routes so you rarely meet others.) This means you will not be able to resupply within the park and you will have to wade. Wading is as you know really dangerous if you don’t know wat you are doing and overcommit. However, if you are an experienced hiker but haven’t done much wading, don’t let that deter you. Lern how to approach it and have an extra spare day for unplanned detours to avoid difficult wading. There is a lot of bears in the forest parts of Sarek but they avoid humans to the extent that you don’t have to take any special measures for them and you it’s unlikely you will see one, You are more likely to see a moose, famous in Sarek for their size since they are not getting hunted. And reindeers of cause, you will see in the whole mountain range.
Hitchhiking is safe and lawful in Sweden, but not so common and it can be difficult to get a ride. Consider flying if you want to go to the mountains as alternative to hitchhiking from south Sweden, unless you want to have stops to experience the southern parts of the country as well.. If you book early you can get a $50-80 flight from Stockholm to Kiruna (for Kebnekaise) or Gällivare (for Sarek).
If you decide to go for some thing like this in Sweden I can help with more details.