I finally got on the ball and ordered the tin ceiling. I went through a couple of different companies to get the best price. I was planning on going with a pattern that I've seen more commonly, but at the last minute I came across a couple that were pretty interesting, finally deciding on this:
I'll have a "filler" around the edges which has a hammered look to it. Then this moulding to cover the perimeter edge:
I've been told that I should see the panels by the end of next week, so we'll see.