We brought all of our electrical stuff with us and just changed plugs. The only things that didn't work were the TV's but these can be used through SKY digital. However, I would advise selling as much as possible and buying again out here - even second hand though the auctions if need be, as if something goes wrong UK fridges etc they are hard to get parts to fix.
Most NZ houses leave cookers/ ovens/ dishwashers as part of the fixtures and fittings so I wouldn't bring these either.
Good luck with your move.