I had a holiday in New Zealand using a camper van about 5 years ago. It was quite expensive as I paid extra for full insurance. You can park anywhere (within reason) so you don't always have to pay to stay in a campground, though the campgrounds are usually clean and well equiped. There were just two of us but we hired a four person camper which was very roomy. I guess it depends on your budget. The smaller two berth vans looked very good though. The roads are easy to drive on, out of the towns there is very little traffic. I would hire a camper again if I return to New Zealand. The best part is not living out of a suitcase as there were plenty of cupboards for storing clothes etc. There are loads of companies that hire campers. The main ones I think are Britz, Maui and Kea. Most companies will send someone to meet you at the airport and take you to their offices where you pick up the van.