Niall, i did 3 days touring there last May. we camped at Turtagro and did tops straight from the tent. (Dont know much about those specific valleys that you mentioned, and at present im in France without my norway maps etc) Plenty dry grassy patches to pitch tent. You can use the shower/toilet facilities in the Hotel for a reasonable fee, and there is a really cool, if a little cold, river to swim in after you get down.
If you go into that Hotel i mentioned, they sell a ski guidebook (skiforer Jotunheim) (in Norwegian), which has some epic lines. Another good guidebook is “toptur i Norge” which you can buy online from http://www.friflyt.no -redirect to http://www.eksponert.no/
Also, DNT cabins can be very useful and cheap.
Watch out for easter - super busy anywhere in the norwegian fells, but will be OK, and very social.
hope to be there myself the 1st or 2nd weekend in May.
Hope you enjoy it!
