I've been closely involved in setting up a NZ wholesaler with ecommerce over recent years. Our server is based offshore for cost, continual upgrading and zero down time plus we get excellent 24 hour service on a server which copes with over 8000 products and a prices updated daily. I've yet to find a NZ host which can deliver the same for what we pay, though many say then can, I haven't been convinced by their promises.
I spent some time in the UK to where ecommerce is a way of life, internet is cheap and speeds are, well higher than here. There are numerous small businesses essentially shipping in from China and reshipping from a small garage - or even their bedrooms. Very sucessful they are too. Their sites are sophisticated. as are their customers to web buying. Check out android ShopSavvy QR and Layer which are well and truly integrated. I would also use Amazon/Ebay for a bit to see how sellers integrate with the buyers.

One of our biggest wake up calls here was the lack of internet awareness and sophistication from our retailers, especially out side the main centers. This is not helped by the slow speeds prevalent throughout the country, something unlikely to improve in the near future.

Technology is moving fast in this area and we are in what seems almost constant upgrade. An ecommerce site can be set up really cheap these days. Host with unlimited space plus dot com plus something like magento/virtuemart can be done for diddly squat. Templates can be added to ensure your site configures to mobiles and so forth. However do not underestimate the resources needed to maintain, upgrade and DESIGN.

I have to say I would be cautious about setting up a MC e-commerce site in NZ. margins would need to be low, population is very low, web use is low, import exchange rates/costs while good now can and will change very easily, and forward currency hedging can all too easy become a liability.
I did look into a MC e commerce busness a short while back but very quickly dropped it. One of the reasons however was the effort required for lack of return, ie ubber low margins. This may not be a factor for you.
I wish you luck however.

Check this outfit for current state of play and note fast download speed of their clients examples.
http://www.holbi.co.uk/