You're probably going to hear different opinions about this topic (search the archives for more info), but in my case when I added factory fogs to my '99 everything was plug and play.
You will need:
1. fog lights
2. fog light relay
3. headlight switch with fog light pull-out option
See if the original threads are still there then let me know if you have any more questions.
EDIT: I just re-read your post. FIRST, check if you have the wiring (I'm pretty sure you do, but check anyway). You'll be able to see it once you take out the covers.
You will need:
1. fog lights
2. fog light relay
3. headlight switch with fog light pull-out option
See if the original threads are still there then let me know if you have any more questions.
EDIT: I just re-read your post. FIRST, check if you have the wiring (I'm pretty sure you do, but check anyway). You'll be able to see it once you take out the covers.