If this is for an emergency, the most difficult thing for you right now is to get an appointment either in Canada if you prefer to go there or even in Beijing. Just checked the website, it says the wait time in Vancouver for a non-immigration visa is 50 days and in Beijing is 29 days. That means you won't even be able to go to the embassy to apply your visas till the day you could get an appointment. You can check this website for wait times in all American embassys around the world http://travel.state.gov/visa/temp/wait/tempvisitors_wait.php.
From personal experience, I strongly think H-1Bs have really minimum possibilities of any problems. I entered US by J-1 visa, and have been going home in the last 3 years without any problems. Last time I was at the American embassy for my visa, and over heard a girl with just bachelor degree and working at Panda express got her H-1B too. Not that I think she wasn't qualified. My point is that as long as everything is ligit, you should be ok.
Good luck!