The other mentioned methods look like a good idea, but if you plan to have them made I will second the recommendation for Aerographics. They are a pleasure to deal with and will work with you to do any custom work you need.
They were very helpful on a PA-11 project for both interior markings and exterior vinyl. When the "Piper Cub Special" decals for the vertical fin proved to have a short life, Aerographics duplicated them in Vinyl right down to the slight imperfections in the lettering on the originals (at my request).