The later the car is, the less it will change at the back end of things.
Virtually all of the stifle of the exhaust note, and performance, takes place up front, on a CF3 engined 147 TS, youve got a pair of Pre-Cats, and then the main Cat, and its these that will make the biggest of differences to noise level and notes.
the back box design, or complete lack of, will change volume levels and notes, noticeably, but nothing like changing the way the front end works.
if you want a deep throater, and an actual performance gain possibility, lose the cats, or at least the secondary main cat, pipe through with a shallow resonator or performance back box, and the tip of your choice, building in the silencing level you want as you work backwards from the manifold end.
job done! or at least thats what i would do.
thats what i would do anyway