This is the layout I eventually chose, with an interlocking pattern. Because I made 75% of the short tile, and 25% of the taller pieces, I ran out toward the bottom. So the two bottom rows of tile don't have much interaction going on. I have a few more of the tall tile I set aside (the best ones) that I was hoping to keep for future projects. But I may end up adding them to this layout, just to keep things cohesive, whether they'll show or not. It would make me crazy to know that the bottom two rows don't match the rest, even though no one will ever see them.
If you doubleclick on any of these images, you'll get a close-up that will allow you to see some of the great coloring in these tiles.
Next step will be to mark these pieces so I can more or less reassemble everything on the wall.