Hmm, totally depends on how much you want to do. I'd say for sure, if you're coming to Toronto, you'll want to do the day trip to Niagara Falls. It's about a 2 hour drive (give or take a bit) with traffic. In TO itself, did you want to go to a TFC game? There's the usual stuff: CN Tower, Distillery District, Beaches, Toronto Islands, Entertainment District, Dundas Square etc etc. I can send you more info once you know your dates and how long you'll be coming here for. We should be in NZ by then. I believe that I've got a year to get there on my Permanent Resident Visa.
If you are going to a TFC game, I can get you in touch with some fans here. They meet up pre-game, and I'm sure they'd be happy to welcome you to the group.