What is the best aftermarket Catalytic Convertor and Exhaust sys. for a Mazda MX-3?

I have a '94 mazda mx-3 4 cyd. manual that I would like to get a bit more fuel economy and power with. I want to put on a K&N air intake, and aftermarket exhaust system on the car. What would be the best option for a guy who likes a a deep low tone and nothing laud? Any other suggestions beyond these modifications?