not sure about an age limit for a work permit - but have been told by immigration agencies in SA that over 45 is a bit harder to find employment. dont know how far that is true though cos' i have met many south africans over that age who managed to secure really good jobs here - guess it depends on experience and qualifications. Ring immigration - that is the best way to find out for sure.
about my brother, he has decided to come and will be doing his best to get in wherever he can. getting his employers back home to give him really nice references so that should help. another question - my brother will be saying on his form at customs "main reason for coming to NZ - to visit family" - does he still have to show that he has enough money for that month even if he is coming to stay with me and wont need to pay for accom. food etc?