I have toured NZ many times having lived there for 20 years (tri national one a kiwi.) You did say any information? Most of my tours were in my car booking motels ahead, and eating out, most motels provide kitchen facilities so breakfast could be inhouse, which left plenty of time to visit cities as well as countryside. If I were to return for a tour I would opt for this way and rent a car in preference to motorhoming.
Naturally all tourists visit the usual sights mostly in the South Island eg Milford Sound, Queenstown, Fjordland Marlborough Sounds, but don't discount the North Island less touristy spots such as the Urerewa National Park, the Coromandel Peninsular or even the Tararua National Park (once my near-home territory)
Except for the renting of a car I've done exactly the same touring several times in the USA using a motel chain and booking ahead, and eating out..... there's always an inexpensive diner nearby. Plenty of time to do what I came for ie see the sights and not spend most of the time in some out of the way campsite or supermarket looking for veggies and tea bags!!
My NZ trips would be for no more than 6 weeks at a time, and the USA sojourns were up to 3 month stints, any longer may be a bit much and this has to be considered. Each to their own I guess.