tried to book a skycouch a few years ago, but at least at that time they didn't sell them on every flight. seems if they could sell all seats as regular tickets they would. paid a little extra for my wife and i to sit in a skycouch row, but never had the option for buying the whole row of three, and airnz sold the seat next to us to someone else
anyway, loved new zealand, favorite place i've been
here is the south island road trip route i took, would do again in a heartbeat
queenstown -> cromwell -> lindis pass -> mt cook / hooker valley track -> lake tekapo -> rakaia gorge -> springfield -> castle hill -> arthur's pass -> cave stream -> devil's punchbowl -> londonderry rock walk -> glow worm cave -> hokitika -> franz josef glacier -> glacier views/hikes -> haast pass -> thunder creek falls -> fantail falls -> blue pools -> wanaka -> roy's peak -> cardrona pass -> cardrona hotel -> and you're back to queenstown.
figure out a way to get out to milford sound, whether you go in your campervan or hire a tour bus
north island i'm sure is find, hobbiton evening tour and feast was terrific
https://ts.la/eric59704