You can try a Cold Air Induction (CAI) Intake. May change the tone of your exhaust. New muffler? Again tone. Nonetheless, they will not offer the same benefits that duals offer. That benefit being your cars ability to breathe better.
Single exhaust can in many cases be far more efficient and rewarding, as seen in Third Generation camaro's, 305's and 350's, of course with the right setup. Today people assume if you do not have dual exhaust, you dont drive a hotrod.
That's wearing off as most of the sport compact scene is adding dual exhaust, neons coming with it factory and such.
Worry more about how it affects your motor, another exhaust system might sound great, but you're not tracking behind your car when you're driving, hell when you're inside, what exhaust you have will make the slightest difference!
Turndowns right at the mufflers on alll of my hotrods none of that chome piping to the bumper