Pretty image. I ca see why you would like a large copy. Whatever you decided, I would carefully check the highlights, soft-proof to makes sure you dont have anything blown out since I think you are close.
Why are you choosing between such very different presentations? Obviously the look of canvas is different from metallic. Are you debating a single image vs the triptych presentation?
Without the question of breaking the image into thirds, I would personally go metallic. You have shimmering sky and water. These elements will dull down on canvas.
Curious what you decide and how it works out. Let us know.
Scott
Decided on canvas with a semi-gloss finish. It was a PITA hanging a triptych setup today. It's going to be flanked by two of my favorites printed at 40x30"