I guess mods are all a matter of budget. Done properly, I would say do the exhaust first. Everything flows from that. But like many of us, we need to start small, so doing a K&N panel filter is a beginning. Removing the air silencer helps (takes only time, no money). If your looking for a good daily driver, then stick with the basics. Make sure the plugs are good, all the wires are good. If your planning on major mods and high h/p, then a chip would be very important. One thing will lead to another, and none of them are cheap. Things will change with our expectations of the car, but remember, its an 18 y/o car, so be careful what mods you choose.
No matter what mods I put on my car, I always make sure that I remember the basics of maintenance, and I am learning everything I can about the car.
Just my 2 cents.
Matt