Both are striking images. If you are doing a wall why not use both. You'll be surprised how many folks will not notice they're the same site. Those that do will recognize the artistic skill that you bring to your photography.
I think the repetitive arches and inside walls of the arch supports show up better in the B&W. To me that draws the focus to the upper left of center.
However, the richness of the color image is striking. The intesity of the sun streaming through the archways draws my attention more to the lower right of center. I did notice the "blue machine" at the end of the passage. I would cover it with the same color as that exit wall.
I'd leave the person in both. It's just another minor detail that makes the viewer look again to find the things you miss with your first impressions.