Hi,
I haven't been here for ages but really need to get back on the wagon again. Re mayo - I would be surprised if you can't get Hellmans in NZ - here it's available in Coles. I have found gorgeous blue cheese mayo and Caesar mayo in gourmet sections of other supermarkets. It's a matter of looking around.
Re chocolate - I think as others do that avoidance is the best answer because it tends to set off a dreaded chain reaction however Cadburys Lite is very nice and cheap. Bit hard to get but very LC. Be careful of nuts - so easy to eat tons and so high calorie which I really believe matters. Cheers. Sally