In the meantime, I have gone through a bunch of my photos from Japan and N. America to find some possible styles that I could try:
The three below are currently my favorites:
Yashiro - Olympia, WA |
Portland Japanese Garden - Portland, OR |
Bloedel Reserve - Bainbridge Island, WA |
If I can find enough flat faced stones from my free source, I might go with the Bloedel style threshold.