for xetrade, all the info you need is online. Yes, you need to register first. http://www.xe.com/fx/
Note that it's only for electronic transactions, you won't get hard currency from them.
I can't tell you which bank you will prefer. Scotiabank might very well treat you well once you have PR. But not until then, not if you're here on a temporary work permit - as far as they're concerned, they have no way to tell whether or not you're a criminal, and treat you as suspect. (At least, in my town...). I honestly don't know if RBC is "better", just know I'm fed up with Scotia.