We did a similar trip last Christmas in reverse...we did BOS-PPT then to Cook Islands to AKL. We went to Bora Bora on previous trip so getting to PPT was just a short stay to catch their flight to Cook Islands. Anyways, PPT international terminal is semi open air so suggest you to book a room either across the street at the Airport Motel or if you have IHG points stay there
5 nights in Auckland is too much, we stayed 2 just because we were visiting a friend then we drove down to Rotorua, it has plenty to see and more interesting in that area! I m working on posting the NZ pics to my blog so PM me if interested!