For business I'd say the best universities would be UNSW and USYD.
If you couldn't get into those, then definitely consider Macquarie or UTS.
UTS- offers 5 bonus points, so shouldn't be too hard. I heard it has great connections with companies and such so job prospects look good. Although the campus is not as nice (one building lol)
Macquarie- very easy to get into I think their atar is around 82. The campus is fantastic, really friendly, laid back atmosphere. Although it is very far for most people, depends where you live. It ranks as good as UTS in terms of job prospects.