Clio RS - wich exhaust?

[Yanoo_]

Hi folks!

My mate would like to buy a cat back exhaust system for his Clio II RS (2001 / 124 kW).
His demands:
The system should sound quiet and good - be burbly (no raspy sound).
Some extra HP would be good too.

Which exhaust do you advise him and where could he buy it from?

(If he had a Valver/Williams, I would advise him Devil... it's not a question :D, but I don't know so good the RS as Valver/Williams.)

Cheers

[Yanoo_]

Any advice would be great!
Cheers