Have a great time, David. Are you going with Bill Schwab? I'd love to make one of his trips some day, either Iceland or the Faeroe Islands.
Whatever you bring - keep it simple. The best camera is the one you're most comfortable with. Don't bring too many lenses, because you'll spend more time thinking about what lens to use than thinking about the pictures. Maybe a brush or two? Oh, one of those things to wear over your eyes to block out the light when you sleep is a heaven sent when the sun refuses to set.