I have yet to hear ANY exhaust on a Focus zetec that I like, even all the setups I've gone through, I hate.
Either too loud or drones or sounds like a wet fart.
Honestly, the FSW Stealth setup is closest to what I'd call the optimal sound, or lack of.
A good system, IMO, will consist of a big resonator and a quality muffler (not Mangaflow). Removing either component makes the car too loud or too raspy.
Don't "think outside the box".
There is no box.
Do it correct, or do it twice.