If you are going to go with aftermarket stripes design some custom ones that only you will have. That way you can make it look better than the SVTPP and can say that you designed the way they look.
Because I like the look of the SVTPP over the top stripes, but want them in silver. And I don't like the side stripes and like my black interior. So, to me, that's pretty custom.
I found another thread on shelby forums that says they are 4 1/8" wide, with 7/8" spacing between them.