Ok, first not to give 98CW a hard time but DC JDM header shoudl cost under $300 and you can find carsound cats for around $120 from places like Hybrid Garage.
Yes it is worth it if you are going to modify things further and if you are tuning you are on your way.
Consider the oem jdm 4-1 since the clearance is better than that of the DC header.