Nice initiative. I hardly use any textures, but some may be very handy. Are they tiled, so you can repeat them? Otherwise I suggest you make them tileable. And I would make those photographs straight from above, without shadows, or they will look strange if you view them from another angle than how they're photographed.
Stitching is great; I used to make landscape images of 8 or so photo's all stitched together, and they hang on my wall now at 2m wide with every sandgrain visible.