This service is run by the NZ post office. Sign up is free and gives you 3 addresses, one in the UK, one in China and one in NZ. Have your orders sent to the appropriate address and You Shop consolidates your shipment and delivers it to NZ at a very reasonable price. Does not handle customs clearance for you, however, just go to the local Customs office, present invoices for all the items and your Temporary Import Exemption form, and clearance should be straightforward. Easy to use website.