You might let us know what you have. It will help you get more specific answers.
As for performance exhaust, don't expect much of a performance boost unless you've already done things like heads, cam, headers, etc. You might get an extra pound or two of torque with an exhaust change but you likely won't feel it in the butt dyno.
The stock system flows pretty well and can handle what comes out of the stock engine.
There are other upgrades that can have a more significant improvement in performance than an exhaust swap. But again, until we know what you have it's kinda futile to comment.
That said, if more bark is what you're after, then that's a whole different ball game and there's lots of options.
Like Wizzr said, let us know what you have and we can help you better. Also, if you let us know where you are in CA, we can introduce you to local Fanatics that can show you what they have done. All that being said, improvements can be made with a custom tune by Joe Delano at www.leftcoast32.com He knows how to coax the most out of you SSR with his trusty laptop.