From all over, though in Canada, not NZ.
Hydroquinone and phenidone or metol - mail order. One order can go a long way.
Ascorbic Acid - the heath food shop
Caffenol - coffee from the grocery store.
Alternatively - one bottle of Agfa rodinal or Kodak HC-110/ilfords Ilfotec HC commercial developers will when diluted as planned , go a long long way.
Sulfite - commercial food processor in the past - sausage maker. Now mail order.
Alkaline - Washing soda - sodium carbonate and borax- sodium borate - grocery store; Pool supply house is an option for the carbonate
Add Lye from hardware store - and with the CRC book as a reference , get to soduim metaborate (kodalk) from the borax, or buffered stop bath with soduim acetate from the vinegar
Restrainer - bromide - from mail order. Or Benzotriazole - much more concentrated - a stock solution of BZT , measured carefully can replace bromide
Stop bath - Vinegar for FB paper, or just water changed from time to time for film and RC paper.
Fixer - Hypo crystals - mail order, with a bit of sulfite and other little mial ordered bits. Or more frequently, 60% ammoinuim thiosulfate, by the gallon jug. Commercial Ilford fixer is just as good a deal, and works the same as most rapid fixers.
TF-4 from Photogrpahers formulary, or Superfix formula from APUG's Photo Engineer, will save hours of your life from otherwaise slow fixing processes.
Spend to buy a copy of Troop/Anschel 'the Darkroom Cookbook', and then build a spreadshet of the common elements that you will need.
I know Claire at JD Photochem outside of Montreal will mail ship all over the world. I get excellent service from her, as well as Mike at Artcraft, and the crew at the Formulary.