University of Toronto seems to be the giant amongst these. Plus commerce is what you're really aiming for, though that's not as important because even with distantly related fields you can get a variety of jobs.
To your second question, it depends on you. Are you willing to play the gamble of waiting another year, only to appear in your SATs? It's not 100% that you will get into said university; usually, high ranking universities have stringent criteria and the most important question for candidates leaving a gap year is: what did you do with your time? And for that, you must have a good answer--SATs are not enough. Students give SATs without a gap year all the time, and if this is the best of the best, they'll want you to be above average anyhow. So, find activities such as internships, jobs, short diplomas or community service you can engage in during the gap year. Not only will that give you experience most other fresh graduates lack, it will give the university reason to not take a fresh graduate in place of you and for all you know, this one year could be a valuable addition to your portfolio for life. However, if you do not intend to juggle between SATs and extra-curricular activities as described, don't wait for a year. Waiting a year and ending up going to the same level of universities as now is of no use.
