From what I understand, Quebec had to recognize Anton Piller orders as they use civil law, not common law.

Anton Piller orders are under common law, so already completely legal in the 'rest of Canada' as you say

Git is usable on Windows - I've used it for the past year with cygwin. However my colleagues mostly switched to msysgit as they had issues with cygwin - msysgit looks like a better choice. Our server is on Linux though - I'm not sure how it will fare on Windows. We went through a few gotchas (crlf, case-insensitivity) but it was manageable.

Manageable is the most I can say though. I've come to the conclusion that going through the trouble of msysgit/cygwin is not worth it. I don't know if it's an option for you but have you considered other DVCS? From what I heard Mercurial is pretty good on Windows and you'd get pretty much the same advantages as with Git. Others might be able to tell you more about it.

I wouldn't go back to SVN on any platform though - I got addicted to local branches and the speed of having the whole repo locally.