I am a big do it yourself type myself, but I am wondering if you are taking on a bigger project than you realize. Here is a pic of all 3 stripes. all three have a curve in them, including the long piece that goes on the trunk lid. The curve in the fender pieces is not a constant curve. To recreate this in a decal would seem tough to me. Were you going to paint it on? Again your man is going to have to be good, because if he taped the stripe off in a straight line, it won't follow the curves in the sheet metal properly. Also, wouldn't he have to tape each of the 4 stripes one at a time? If you just want the width of each of the four stripes and the width of the spaces in between them, I can do that. If that is what you need, inches or millimeters?
I am very doubtful you could find a stripe in that color. Most companies that repop items stick to the oem colors. The colors available for 68 1968 R/T and Bee butt stripes were black, white, and red. On an unrelated subject, does it seem strange to anyone else that while looking this up on the options list I noticed that the available colors for convertible tops were black, white (OK makes sense), and GREEN? What color body color would go with a green top other than green?