You could do two things. You could do this my digital imaging on canvas. This would be somewhat costly, but the end product would have texture and look more like a painting than a photocopy.
Digital imaging actually on any medium would give a quality product. It just depends on how much you are going to sell them for, and how many you think you can sell. Imaging can be quite costly, but it's the most efficient way to get each print to the size you want, and on the materials that you desire.
I used to sell prints of my artwork. Doing the unit pricing on this can get sort of wiggy, especially if you are concerned with having over-stock. It's the reason I only sell originals now.