1994 Chevy Camaro...?

I have a 1994 Chevrolet Camaro. It is a 3.4L V6 and the speedometer says it only goes 115mph... I want a fast car that can keep up with my fiance's 2003 Mitsubishi Eclipse (3.0L V6, but his goes up to 145mph). What can I do to the Camaro to make it go faster or get more horsepower? I am putting a dual exhaust system on it, it has no catalytic converter (the dealer took it off before I bought it, which is why they are no longer in business), and I know new headers would help, too. But what else is there? I've checked e-bay for stuff, but I just can't seem to find much stuff... Any advice on what to do and where to get it from?