where's the best place to buy an exhaust for my rx7 something that's more factory

 

The closet to factory you can find is a racing beat setup. They are one of the best, and they are pricey. But, they last longer than factory

 

Another vote for Racing Beat. Sounds good and worth your money.

 

I have put Racing Beat on all of my rx7s. Sound is perfect and the quality is the best out there.

 

Not sure about Indiana laws but I hear it is healthy for the car to de-cat the exhaust. Something to consider if you don't have to pass an e-check.

 

That helps a lot when you have an old cat that is clogged and you are too broke to buy a new one, but on a non-turbo street car a good cat will not restrict the power by a considerable amount. The downside is that it is technically illegal at the federal level, and it lowers the resale value of the car.

 

You probably heard that from someone too cheap or broke to buy a replacement cat. Like it's also healthy to chuck the AC since it broke. Or toss the PS since it started to whine.
As Evil mentioned, a quality cat doesn't hurt power that much. It also quiets the car. But most importantly IMO, it keeps the eyes of anyone standing within 20 feet of your car from watering, and keeps clothes from smelling like a hog farm. Not sure what year RX7 the OP has, but in some circumstances on a FD it may also lead to boost creep. And that's far from healthy, since it can cost you an engine.

 

I've never had any problems before with my decat, just check the laws in your area first.