What sport exhaust for Cooper S R53?

Hello Minifriends, I hope the question has not been answered x times by you (I hardly found anything via the search function). So, my question to you: which sport exhaust (with ABE) would you recommend? I have now repeatedly picked up the names Hartge, Eisenmann and of course JCW. Where would you buy it then? And what about the pre-smuffler theme (pure/out)? Thank you in advance for your tips!!! Many greetings, 29palms