I just had this thread pointed out to me.
As Flyin Dutch wrote, we went via the Faroes and Hofn on the South East tip of Iceland. We chose this route (in preference to the route that Flying Femme gives) because we had VFR only pilots with us, and the conventional ferry pilots' route forces you to remain below FL55 over a large tract of water because of class A airspace. Even routing via the Faroes at VFR levels you will lose VHF contact for some time. Routing more directly, you will lose it for a large chunk of time.
Combining that with a piston single may exceed your risk appetite... and that ultimately is one of the biggest elements in choice of route.
I would endorse Wick Airport as others have done Andy Bruce at Far North aviation is an old hand at this game and knows all the tricks. Unfortunately, Wick town is a complete dump though, so I'd probably aim for Kirkwall as a stopping off point in preference having now had the Wick experience once or twice. For a first time, put up with Wick town, and benefit from Andy's experience.
Feel free to PM if you want more details or a chat.
2D