The headboard of my king bed is 77 inches wide. I want to have a photo transferred to canvas to hang above it. Ideally, I want a single canvas, though I will go to a diptych or a triptych if necessary. I think it should hang beyond the headboard 3-4 inches either side, making it 85 inches wide, and therefore the height should be about 40 inches. And I would hang it eight-ten inches above the headboard. Any opinions?