Originally Posted by djburke87

Can a car be tuned without catalytic converters?
Absolutely! In fact, test pipes are generally a great bolt-on power upgrade and a tune is necessary to take full advantage of that power.
Am I ruining my car by not having them?
Absolutely not! Anyone that says differently is trying to sell you something.
Does anyone know a good tuner on the central East Coast that would tune a car without cats?
Hills Garage and R/T Tuning are both very reputable shops that have significant 370Z tuning experience and are not terribly far from VA
If I do get cats, which ones should I get to make the most power?
HFCs will give you more power than OEM cats. There are a number of vendors to choose from. I recommend Fast Intentions.