While you wait for a more specific response, you might want to have a read of these recent threads regarding campervans in NZ. They might answer some of your questions.

http://www.fodors.com/community/australia-the-pacific/road-trip-to-ni-and-si-on-a-campervan-versus-motels-and-bb-in-august.cfm

http://www.fodors.com/community/australia-the-pacific/hire-camper-van-or-car-plus-motel-for-30days-in-nzl-from-9dec-6jan13.cfm

http://www.fodors.com/community/australia-the-pacific/wicked-camper-dont-ever-hire-from-them.cfm

http://www.fodors.com/community/australia-the-pacific/camper-van-in-nz.cfm

We hired a two berth Fiat and it was quite spacious. Although we are used to a much smaller van. We currently have a Toyata Hiace.

The NZ vans tend to have the kitchen and showers up the front and the bed/dining table at the back so you are surrounded by windows when at the table. The beds are usually queen size or similar. This way you have the sense of more room and a clear view. They have plenty of storagespaceas well.

We never stayed in camping grounds last trip so can't comment (However when we stayed in them thirty years ago they were very good!). You know you don't HAVE to stay in commercial campgrounds. There are plenty of places to freedom camp.

I suggest you go visit your local campervan hirer/seller and have a good look at what is available.

From the questions you have asked it seems that campervans might not be your thing. If you plan to only stay in commercial parks, then there are cheaper yet more luxurious ways to travel. If you plan to be out in the bush then campers are fantastic.

How do you normally travel?
Why do you want a camper?

Thank you for all those blog threads, Melnq8! You are filling me with much needed information to help in my travel decisions!!
peterSale - I appreciate the detailed response. Since we are exploring the Southern scenic route for 2 weeks and moving to several different locations, we thought a campervan would be helpful to have a "home on wheels" rather than packing and unpacking into numerous hotels. We thought it would be cheaper as well, but after reading more, there are a lot of added expenses to consider so we will now need to do some comparative pricing on other accommodation options. Do you have suggestions for other cheaper, yet more luxurious options? I am typically a hotel stayer, but wouldn't mind the camper thing, but was envisioning them bigger and more spacious than what I saw on the internet so I got a little discouraged. But I suppose that would be even tougher on the roads there. So much to consider!! So I am leaning towards looking into other places to stay, so would appreciate any advice in that regard. Following are the spots we are thinking of stopping at:
Christchurch - Marlborough Sounds - Nelson - West Coast - Queenstown - Te Anau - Mt. Cook
Thanks in advance for more suggestions!!

The average hotel/motel/cabin will be as or more luxurious than a van and cheapers except that you can't cook in a room.

I noticed on your other thread you are from California. As I said above go to your local dealer and have a look at some vans. If in any doubt hire one for a couple of days.

We are biased. Campervans are the preferred option. Anything else is 2nd best.

Why do you need to pack and unpack all the time? If you are going from hotel to hotel, leave most of your luggage in the car and only take into the room what you will need for that night - toiletries, book, change of clothes (if needed). Use a small backpack etc. (we've even used a shopping bag!)

kktravelbugs -

Just an FYI that the Southern Scenic Route is only the area between Queenstown and Dunedin. I'm confused as to your plans now that you've added Christchurch, Marlborough, Nelson, the West Coast and Mt Cook.

Have you scratched Australia? Are you now planning two weeks on the the South Island?

Motels, cottages and cabins in NZ generally have cooking facilities. Hotels don't.

Thanks, guys. I will take all of your advice into consideration. We will take the tip to go to a local dealer and check out the campervans, and renting one for a day or two is a great idea! And I will look into the cottages and cabins since cooking meals in is also preferred. We did decide to scratch Australia and just spend the two weeks this round on the South Island. Again, I appreciate all of your assistance!!