Hi folks. Newbie question here that you've all probably heard 200 times, but I'm looking for specific answers not satisfied by a search.

I have a stock '95 GS-R with about 90K mi on it. I need to replace the stock muffler (annoying rattling hole in it) and maybe the mid-pipe. Since I already have to get a muffler, I'm debating about sinking some extra cash into it and putting on a higher-performance exhaust.

I'm ONLY interested in performance. I'm NOT interested in improving the looks or sound of the car. Just enjoy driving my GS-R. As a matter of fact, I'd rather it isn't the loudest or most conspicuous ride in the neighborhood (unless it gets me 20 BHP)

Given my goal of performance, would the extra cash be better spent on the muffler upgrade or a nice cold air intake (I'm looking at AEM)?

Would just the cat-back muffler upgrade do me any good, or would I need to upgrade the header also to make a noticable power difference?

If the muffler is the best choice and will actually give me some noticable power improvement, any advice on brands (from those who've actually done this to their rides!)?

I see DNX catalogs at a lot of the parts shops, but I don't see too much info on DNX on the net. What other brands? Greddy seems to be well thought of on the net.

Thanks in advance,
Erilar