Open work Permit for Spouse and getting OWP at port of entry

[aman04]

 Hi, I live in United States and My Fiance is studying in Canada. As i understand i am eligible to get open work permit In Canada if we get married. I have Canadian visitor visa, My question is if i go to Canada as a visitor and get married to my Fiance in Canada will i be eligible for open work permit.
Another question is If i apply from within Canada it will take almost 75 days but application at the port of entry would be quick. So which would be a better option staying in Canada and apply for OWP or coming back to US and reenter Canada and apply it at the port of entry??