If the interceptor has the 3.5 Ecoboost the mufflers should be the same. Most of them have the 3.7L engine though with different exhaust.
It would be cheaper to go with a quieter after market muffler and have it welded in to the existing exhaust than have a whole new/used one installed. Alternatively you could keep it as is and have resonators welded in before the mufflers which would certainly quiet it down. That's basically how the factory does it anyway... Cat -> Resonator -> Muffler