Note that you can always go to SIBT, and then transfer throught to UAC to UTS- yet they may take into account your ATAR. If money is an issue, and say if you get an ATAR in the 60s-perhaps you are better off doing commerce at say, ACU and then transfering- you will need to get good marks at uni however.
To go from SIBT > Macquarie, you'll probs need to pass all your sibt subjects. for uts insearch, you'll probs need a credit average
http://www.insearch.edu.au/Courses/Business/Pathway-1?tab=3&cnty=Australia1
As for what university is better, Macquarie and UTS are similiar in terms of prestige, income, employment, but I think Macq may be a bit further- I don't know much about that.. Check bonus point elligability, etc- most pathways either take 2 years or $20,000. When making the decision, think about things such as electives, social life, university reputation, location, oppurtunities, majors, etc.