I'm guessing Canada and Australia would go for an EFTA 'lite' type deal. As EFTA doesn't require a customs union it's probably the easiest to implement and build up from.

I think they amended EFTA to require free movement which was a no-op as all the EFTA countries had free movement with the EU. I could see the EU agreeing to a NAFTA style workers visa if they really wanted push the freedom of movement side hence the 'lite' bit.