I have been fortunate enough to go to OZ and N.Z and travel round both a little,,, go to iether or both of these countrys, all those things you mention , pluss loads more . oz and nz are full of adventure stuff,, we went body boarding down these huge sand dunes in NZ and drove up 90 mile beech.
check out air new zealand,,, they have loads of special offers,, with multiple stops in difrent countrys and you can ofton vary the length of time you stay in each country.
by the way your doing the right thing,,,, life is about experiances,,,, not about keeping up with the neighbours new car.