I'm not from the Ontario area, but am in Canada (in BC).
I did quite a bit of searching and researching of the available host agencies in Canada.
I almost signed up with ECSC but as I was looking through the contract, it turned out that the percentage of commission you get with them is extremely low. I was originally told 40% (which was lower than I wanted, but I was willing to work with to get into the biz), but then after looking at the fine print, turned out there were more percentages and expenses that would be deducted from that, making it even lower. So I stopped the application process with them right away.
Of all the companies I looked into, NexionCanada was the one that stood out for me. Here in BC there are some strict requirements and licensing involved and NexionCanada is taking care of those and walking me through all the hoops. And I still get to keep 70% of the commissions, and as I grow and earn more, I can change to a better package that will give me more of my commissions.
So definately check fine print of the host you choose, and also make sure of the requirements for your province and that your host agency complies with them and will help you to comply with them as well.