The first four are grammatically correct, and the verb would not be necessary. The second four are much more common in everyday speech, but not formal writing, because the pronouns should, technically, be the same as those in the first set. As for the photograph, you can think of it as a picture 'of us' or 'we are in the photo'.
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YankeeHi Kooyeen
As regards the specific sentences in this post, what you see as being grammatically correct will not be seen as being grammatically correct by everyone in all contexts. That's why I advised avoiding the problem in formal written English. Sentences 1b-4b are sentences that hard-core prescriptivists as well as enthusiastic descriptivists can agree o