Just bear in mind that whatever one you do end up getting, you will need to consider how you are going to get it out to NZ and back - by this I mean in terms of whether you'll take it as hand luggage (bearing in mind the 7kg allowance on SQ) or whether you're going to put it in the hold.
I did the latter and wrapped it tightly in bubble wrap (several layers) and it seemed to do the trick. However, there is never any guarantee with hold baggage. It's amazing the number of bags you see turn up on day one, week one that have had a huge chunk taken out of them by being put in the hold with no protection.
So if you're family are going to get you a decent one, you may want to consider only taking it as cabin baggage and restricting the amount of stuff you put in it so it's within the allowance.
Maybe not quite answering your question I know, but hopefully helpful nonetheless.
Streety