This project is fantastic! I ran into you at Pintastic this weekend, and thought it was such a great idea I had to look up this thread.
I have a craft cutter, and would be happy to cut you any stencils you might need. The Silhouette craft cutters have a PixScan feature that lets you print something on a computer, then the cutter can cut our around the print. The software handles the alignment/registration automatically. That could be very handy for trimming around decals.