Info request

Afternoon all, I’m in the middle of deciding what gear to take with me for this journey. I use an msr pocket rocket that uses Isobutene-propane canister fuel. Will I be able to find reliable resupply options tramping around the south island? I have no determined route as of yet, and have as much time as wanted to spend hiking. I tend to be on the lighter side with gear and was wondering what you think about using trail runners? I hike in trail runners all over the Sierra Nevada (apples to oranges I know) and I’m very comfortable in them. How are the biting bugs in Oct – Dec? What do you use as bug repellant (deet)? I would also like for any suggestions on a variety of non-touristy tracks that will allow me to traverse many different ecosystems. I’m game for moderate to strenuous tramps, my concerns are major river crossings (I’ll be solo) and intense route finding tracks. I will have gear for all conditions including a TarpTent. Also if you have any suggestions on good track in Australia I would greatly appreciate them. I look forward to picking your brains until my departure… Joel