Ashley,
Not so sure about in New Zealand, but over here wick is very simple to get, as John noted also in the US.
You can buy imperial wick by the roll at either of these suppliers. I use them for restoring Duplex table lamps.
www.johnmoncrieff.co.uk
http://oldflames-lamparts.co.uk
As for the glass, Roger Mills of the Hetherington Lamp Company can get 'custom' glass, I expect sourced in the UK, I've never dealt with him via e-mail, usually see him at the shows or pop by as he is fairly local to us. However I do know he does regualry work away from home, and may therefore may not be able to pick up e-mails so be patient.