In my opinion, the Mallard image will make the nicest canvas print.
One thing to keep in mind with the canvas prints (a.k.a. "gallery wrap"): The entire image is printed on canvas, then the canvas is stretched around a frame. The outer edges will be wrapped around and behind the frame, so that whatever is along the margins will be "lost". It's similar to having the image cropped slightly. With the Mallard pic, this may result in the mallard furthest to the left being right on the very edge of the frame, as opposed to being placed nicely within the margins as it now appears.
