Rotel are one of the brands that won't allow shipping for online orders. Whether that is for country specific price controls or some other reason I don't know.
If you goto any of the online resellers (like hifix, superfi, petertyson etc.) you can see which items are marked instore only.
I recently ordered a Leema Pulse amp from Sevenoaks Sound & Vision in Brighton through their ebay store. They were happy to ship to Sweden, so Norway shouldn't be any problem either.
But again, it may depend on which brands you are interested in. I know that there are sometimes restrictions on shipping NAD and B&W over here due to Hifiklubbens exclusive rights to sell.