I'm currently using Continental Travel Contacts in 26 x 1.75, but while they've been tough as nails and work reasonably well on all surfaces, they're also very wobbly - enough that it really affects handling. My wife has Schwable Marathon Pluses in 26 x 1.75 - they seem much higher quality, but are ridiculously heavy. I have the Marathon Supremes on my shortlist, but didn't know if they'd be sufficient for gravel or less technical mountain bike tracks.
We aren't going to arrive in Auckland until January 28th and we plan to take transit to the south island to avoid traffic. We figured that doing the south island first made sense so we could move north as the weather cooled off. We do plan to camp some as it seems like we'll be able to explore more out of the way places (especially in the far south) if we don't always have to rush back to town before the evening.
Now I just need to get a copy of those books.