I've used Megagoods several times, and they have always been very trustworthy and professional. The only complaints I've heard from a few of my buyers is that some of the products they've sent haven't worked properly and have needed to be returned. And naturally, the buyers have held me responsible for those products not functioning properly, since most buyers don't understand the concept of dropshipping and the fact that I never even see the items myself.
Other than that, as long as you're okay with paying their monthly fee, I strongly recommend Megagoods.
As far as importing the items to your location first and then reselling them, I don't recommend doing that, unless you plan to only sell the products to people in New Zealand and Australia.
If you're planning on marketing the products to buyers in the U.S., it would be very difficult to make any sort of profit if you ship the items to yourself first.
First of all, you would have to cover the cost of shipping the products to yourself first, and then, your potential U.S. buyers would have to be willing to pay the much higher shipping costs for you to ship the items from New Zealand back to the U.S., which is unlikely, considering how many U.S. sellers will be selling the same products from the U.S. in competition with you.
My suggestion is to dropship the items, to have Megagoods send them directly to your buyers. That's what I do most of the time.
I hope that helps!