Hi Melissa, I just googled quilt shops in NZ and found the following for South Island.
http://www.reocities.com/Heartland/Estates/8873/Southisland.html When we visited South Island last spring we visited
Christofer Robyn Quilts
641 Ballantyne Road (airport end 7kms from town)
Wanaka 9382, New Zealand
(03) 443 1810
Open Weekdays 9:30am-5pm; Sat 10am-4pm
It's a small shop out of town in the countryside. As we were on a coach tour we didn't have our own transport so it was the only quilt shop I got to but the ladies were very friendly and helpful. I hope you have a great time.