I've seen other media get at the issue of multiple-personhood, though I'm not quite sure whether in quite this way. But it didn't feel entirely original to me, no.

Really manipulative!Doctor interpretation, upon further thought: he made it Rory's choice because he knew making it Rory's choice would mean aged!Amy would grant Rory absolution, and that was the only way to break the moral deadlock and resolve the situation. If you interpret it this way, he is, interestingly, using exactly the same tactic Amy did earlier in the episode: push aged!Amy to make the "right" choice by making it about Rory.

I can totally believe this, actually; both Amy and Eleven know Amy so well, after all.

I don't think it was Rory's choice at all, though! He agreed with aged!Amy's conditions to save both Amys, and putting aged!Amy outside the door made it about one person versus everyone else, which under the circumstances isn't much of a choice.

What's most interesting to me, really, is that he tried to make the destroying choice anyway. That's Rory all over, really, and why I love him.