Just out of interest, is JURAN a make of exhaust? 
If sound is an issue, you really don't want to be considering anything other than a HKS Silent Hi Power (or a system you're 100% sure is a similar loudness). They're currently on offer with Nengun and will ship to your door for under ?400. That's for an all stainless top brand exhaust.
You get one over 95dB and you'll regret it the first time you go on a long motorway drive... Roland says his was noticeably louder than the 98dB system on his other S15. And his Juran wasn't running with a front pipe, turbo elbow and decat - all of which will raise the noise even more.
Yes, you can stick a bung in a loud system on a track day. However, one of the main reason people claim to not want a Silent Hi Power is because its restrictive (yeah, over 380bhp...). Just how restrictive do you think a system is with a fook off bung in it? On a day when you want all the power you can get....