Stolarz looks like a better option and he's already under contract. If the Ducks aren't bringing back Miller then the former should get his shot at the backup job, perhaps also a one year extension to fulfill expansion requirements. In that event we would need an AHL starter or perhaps someone to partner with Dostal but there are options available in free agency.
I agree with this. I think it makes sense to see what they have with Stolarz - reports are he's much improved.
The other issue is expansion. It seems to me they need to either sign Miller to a two year deal with a blended AAV or extend Stolarz. There'd be little expectation Miller would play the second year, but the ducks pay extra to spread the cap hit over over two years and meet the expansion draft requirements. They can bury him the second year if they want.
If they don't do that, then they need to offer Stolarz the backup job and extend him for expansion draft purposes. My guess is Stolarz won't sign an extension unless he's the backup.