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!
1x 500mW 405nm Projector
1x Homemade 1.2W RGB Projector
1x Lightspace Color Ray Series 6W RGB