Kevin, since I'll be cycling, I'm planning to buy panneirs for the bike so I don't have to lug anything on my back.
I'm currently looking at a 40L pair of panneirs for the back of the bike (20L each...should be enough since I'm going to travel super-light.), and possibly some small, front panniers. I don't know. I'm looking around right now, and will somehow even it all out.

Cdstg - thanks for the help! Actually, I'm already a member of AAA (unfortunatly, I have to drive a car right now.), so I will most definately be checking in with them to get maps and such.
I've been planing to go in October-ish. The seasons are opposite there (from the US) so I'm guessing October is spring/summer weather, right?
(by the way, where in NZ are you located? I may have to hold you to that couch offer. )