Shipping a saddle from the US to Norway costs $80 (cheapest way), so be sure to factor that into your cost. Also remember that it will be almost impossible for you to return a saddle if it doesn't fit, so either you need to be prepared to resell it in Norway if it doesn't fit (you'd probably make a profit reselling it), or look for a saddle make, model, and style that you've already tried on your horse, so you know it will fit.
I've brought saddles from the US to Norway before for the very reason you're trying to do the same, so I understand your motives. Here's what I would do:
Find a saddle in Norway that you like and which fits your horse correctly. Preferably, find several different ones. Look for those exact saddles on US websites. If it's a reputable store, see if they can ship to you. Don't rely on private parties on Craigslist or eBay
to securely take your payment and ship correctly. If you know someone in the US, they can pick up the saddle for you and possibly ship for you. Or since so many Norwegians travel so often to the US, see if someone travelling to the US can bring it back for you. I have brought saddles to Norway as hand-luggage before at no charge. They fit very nicely in Icelandair's overhead bins
I go to Norway twice a year, but I usually don't know when, and I go on short notice or I could bring one. I assume you want your saddle soon, though?
Are you looking for new or used? Top of the line or something more modest?