Like I posted before just upgrade your Mach 1 to what you want, it is easy to surpass the Mach 1 with hp with parts and programming. This way you know everything fits and works together plus you can upgrade it to the level you want and not be locked into a package from ford.
For an oem Mach 1 decal I am pretty sure they are one piece but there is third party that you can buy them in two pieces if you are wanting to put your own color there.