I have considered that very combination in the past. In general, I'm not a huge blue/black combo guy (at least not with clothes). But the blue-dial SOS looks almost gray under certain lighting, and I think the black OR would look good with it. Like you, I've never seen one in real life. I love the circular pattern on the dial against the circles in the OR strap.
To my eye, the dial color on that japanese fitting site looks just a touch more blue than the real thing, but I still don't think it looks bad with the black OR. My vote is black. I also vote that you post pictures here when you get it!
