Sorry here are some other photos...

A really good color is Benjamin Moore Revere Pewter. Behr has the color formula, and can match it. With your furniture being dark, I'd stay fairly neutral so you at least have some contrast.
http://houzz.com/photos/1291372

Go one or two walls darker gray, then the rest lighter gray? I painted one wall dark gray one wall red.. Now,wish I would have gone even darker on the gray.

I think u will love your choices! Maybe switch the colors and do the darker one in the dining room and the lighter one in the living area. You may have painted by now lol, post pics please.

Thanks for the advice everyone. Yes, I love reserve pewter!! I was thinking of putting reserve pewter on the back wall of the arches and then mineral on the front for a contrast. I just didn't know if these colors would make the room look smaller. Lucky we have tons of natural light.