Forget the Sky tower(hold middle finger up against setting sun..looks the same!) go to Tiritiri Matangi Is. instead. IMO
There used to be a Wildlife park at Ti Point, Leigh. Someone may know if it is still going, was very good value. Also just up the road a bit from there is Goat Island Marine Reserve , Takatu Pt has some beautiful Beaches and rocks....4 days isn't enough!!
Book a summer at Coromandel......forget Auck. central!