I would read this explaining the differences between Outland and Inland,
http://britishexpats.com/wiki/Spousal_Sponsorship-Canada
Ultimately it's your call no one can advise what is for the best. Most people choose outland as it's generally quicker, you can leave canada without the worry of your application being cancelled if you don't get re-entry for any reason, and you have the right to appeal if your application is refused, unlike Inland.
You mention working, Inland currently offers the pilot project for a work permit, explained in the link above.
You would have to wait until you get your PR, there is no work permit pilot scheme with outland applications.
you will be on implied status in 6 days when your visitor visa expires, until you get a decision regarding the extension. If for some reason this was refused and you are out of status before CIC receive your inland PR application, I believe you would not be eligible for the work permit as you have to have a 'status' visitor or implied to qualify. (open for correction)
Just a point to note... Outland requires a whole different set of forms, so you would need extra time to go through that all again.
Hope that helps, good luck