I've got the Ragazzon unsilenced tail section and it's the perfect volume on it's own - slightly louder than I was thinking when I ordered it. As a Spider owner I was particularly worried because roof-down there's no escaping from exactly how loud your car is, but after a brief initial panic (wait for the soot to get in - it's a bit mad without!) I'm very happy with it. It's very present when you've got the taps open, but you can easily do long journeys without annoyance.
I've got an OEM centre section, and if it went (again) I'd replace it with the same. If your centre section is still just about hanging together, maybe order just the tail section first and then see how you feel? For the sake of ten quid extra P&P for two deliveries it'll be worth the flexibility.