Not sure, but I am sure I see them at almost all the stores, ICA, COOP, even some of the middle eastern stores here in Kista. I can check tomorrow to see if i am wrong.
I was wrong, I apologize, seems there is a brand of cheeses that is close to that and that is what I was seeing all over the place. Sorry.
Here in Malmö, I have seen Danish fontina at coop-xtra. Otherwise, you maybe could try using Danbo as a substitute.
I have seen fontina at ICA too. We have a kvantum one that has tons of imports and a nice cheese section. I would suggest looking around where you can find proscuitto and tapas by the deli section.
I've found fontina at the italian cheese store/deli on Odengatan and I've found guanciale for anyone who cares at NK's food store.