Just do a Catback for a bit of sound and leave the headers and cat.
Changing headers will make quite loud. And a Loud Auto Civic isnt very fun. It'll drone heaps and probably be bit farty.

If I were to dump $1,000 - $1,500 I would spend on parts that makes the car more enjoyable to drive.
-Sound System
-Coilovers and a RSB
- Or just a nice set of wheels and lower it on springs.

Me personally, I'd get coilovers Drop it on its guts lol

Heres Bae