With the change of location for all Inland applications now being Mississauga, I suggest you call CIC and ask one of their highly trained call centre agents about this. There has been much discussion about this issue in this forum and people are getting conflicting information.
Prior to Jan 17, 2014 an OWP could be submitted with an Inland applications, since both applications were processed at the same location (different buildings). Now, your Inland application goes to Mississauga, but they do NOT process OWP applications there...those are still being processed in Vegreville. So, for that simple reason, you cannot send them together any longer. Plus, the OWP application can't even be processed until you have your AIP (Approval In Principle), otherwise it would be denied. You should write in bold letters, across the top of the first page, `OWP WITH IN-CANADA SPOUSAL SPONSORSHIP. PROCESS AFTER AIP'
The form that you want is IMM5710, but again...call CIC first to see if this really does give you the implied status that you're asking about. If it turns out that you are told that you have to wait until you have AIP before you can submit the OWP (which is what others here have reported recently) this may NOT give a person implied status any longer.