I'm going to follow this post for the math. I need to start brushing up on my safety calculations too. As of now though, I'll limit my advice to that of building a projector as I'd probably mess up some calculations. Looking forward to seeing the progress of your installation though. With some modules from DTR and a few other parts from various sites you can definitely get some good power at a reasonable price.
I assume Canada doesn't have the same requirements for projectors as the US, do they? I wish I could use my homemade projectors in public. For now though, They are confined to my bedroom and living room. Good luck!