Kelley and I are currently touring in Iceland. If you're thinking about doing this trip yourself- I definitely suggest a MOUNTAIN BIKE. Wow, some of these roads are rough, and the big tires make it so much more fun. You can leave vehicle traffic in the dust on the F-roads!
My bike is a Surly Pugsley with 29+ wheels. About 69lbs without food/water. Love the Old Man Mountain rack, and the tires.
Kelley is on a Surly Ogre. Her setup weighs about 60lbs without food/water. Kelley loves her Rogue Panda framebag and her cargo net.