Re: Right of permanent resident fee , pay after SA or wait for landing
i am a bit confused by your timeline. are you an inland or outland applicant? I don't believe inland applicants get "SA", that is for outland applicants. Generally "SA" for inland is called something else, as it's part of AIP i believe.
the fee has to be paid BEFORE approval. the application can NOT be approved without that fee being paid, so it's impossible to pay it "at" or after landing.
you can either pay it now (sending it to the visa office per contact instructions in the SA letter) or wait for it to be requested by the visa office when they are ready to issue the approval. The sooner it's submitted, the less likely there will be delays getting the approval issued.
If you are inland, i would imagine you would need to pay the fee prior to your landing interview, since the receipts are required documentation at the interview.