Logan,
As was said above, if you and the instructor fit in the 152 it's a great trainer. I had a few students, we just couldn't fit comfortably in the 152 and there were some weight issues. The 172 is going to cost you a bit over 1000 extra when it's all said and done, don't know if that matters to you. And I don't recall if you guys down under have an endorsement for each model of aircraft or if the 152 and 172 are considered one type. You'll probably want to upgrade after you finish your training to give your friends some rides.
As to feeling ill, doing the intro flight on a breezy day isn't the best idea - remember that when you take your friends up. Think about it, humans have spent tens of thousands of years walking on the earth at 4kph. Now you go zipping along a couple thousand feet up at 100 kts. No matter how geeked the higher brain is about learning to fly, most of the brain is saying "This isn't right, this isn't right." And even the frontal lobes are in overload. Give it a couple flights to evolve.