WOAI isn't hard ... just a little time consuming to begin with, as you'll have to grab all the airlines you need first (eg. All relevant to NZ) then install them one by one, plus the GA aircraft. For WOAI, you can just select the major airports in NZ - it should then list all the packages you need to grab. The actual models are pretty good (all the aircraft are included in the airline packages) - way better than my Ultimate Traffic (which isn't updated very often anyway).
Once the initial bit is done, it's just the odd package every now and then - usually "flagged" by someone here (as above).
I wonder when we'll get Jetstar?

You don't need to install the one by one. Select them all, then hit install!