I've been there a few times, sounds like a good deal. You are def in the right area, Paradise Island near Atlantis, other areas can be sketch!
Atlantis is badass you have to go on the waterslide and the aquarium is intense. There is a Casino there too which is amazing and was empty when I went. Quick walk up the street and you can rent some jetskis for pretty cheap and feel free to beat them down on price and go shred some waves.
Hay Market is cool for shopping. I was there to watch the old one burn down... it was crazy but I hear the new one is aight. OK nightlife downtown but go at own risk, there are some bad-mons hanging around at night.
I would skip the "exotic car" deal, the roads are shit and the drivers are idiots. I'd say spend that cash either on the racing boat sailing experience on New Zealand 1 or the jet ski trip through the islands and see the submerged plane and abandoned mansion owned by the real drug dealers that inspired the movie Blow.