Given that most stores would not carry them as a stock item, you could be pushing your luck. Best you might do is to take your projector into somewhere that has a projector demo room. These are getting hard to find now though with the big box retailers, you will be stuck with the more specialist stores.
Ive had 2, a cheap n nasty TM style screen, curved in at the sides within about 6 weeks and got some nasty discolouration in the middle. Fabric was always viewable with my projector.
Got it replaced via the retailer (harvey norman) after some "discussion", they replaced it with a Rapolloav screen.
Is 92 inch wide, manual pulldown. Still happy with it, no curling after over a year, still operates as smoothly as it did the day I got it, screen fabric is invisible, gives a good picture.
Would recommend one anyday, would not recommend a cheap TM one
Unfortunately NZ has always had a limited range of projection screens. If you want a high quality screen, you probably need to talk to your local Hi End audio visual retailor or as the previous post recommends, Rapallo. They carry modest quality screens with good hit power for buck and reasonable range.
For demos, you are asking a bit much, because they are so difficult to freight without damage it is a no go.