Hallo strukki
I can tell you about New Zealand, but not Fiji. I am the manager of Kiwivelo a training camp and bike holiday destination in Nelson and Taupo in New Zealand.
A german drivers licence is good for up to one year in NZ.
You should have a tetnus injection if you haven't had one recently.
For a website about NZ info have a look at my company website
www.kiwivelo.com (auf Deutsch)
Any other questions I am happy to help.
Freundliche Gruese
Tim Vincent