Ken,
The EBC green pads are not recommended for track use. They will wear away just too quickly. Your stock pads should work fine for one track event, as long as you check them after each track session. (Of course, you can go as far as you want concerning brakes -- pads, rotors, stainless steel lines, air deflectors, big-brake kits.) If you're doing a couple of schools, you may want to consider a set of dedicated race pads; there are lots of pads out there -- Brakeman, Performance Friction, Porterfield, etc. -- everyone has his or her favorites. Of course, then you need to consider that race pads may wear your rotors...
My personal recommendation, for your first event: Keep it simple. Change brake fluid just before the event to Motul 600 or equivalent, and stick with your stock pads (unless you've got a lot of miles on them). Optionally, add a pair of brake air deflectors (Tittle or Woodhouse have them). If you're going to drive really aggressively on-track, you will not be satisfied with the stock pads, in which case you will need race pads for both front and rear, since you should use the same compound front and rear. After two track events, race pads may wear your rotors enough that they may need replaced; if not, at least turned.
I doubt the stock pads will last more than one event. There are lots of variables here -- driving style, braking technique, track, etc. -- which will affect how quickly your pads wear.
(JonB at PartsRack can help you with your various options. He's pretty knowledgable about this stuff.)
My 2001 GTS is a street car, definitely not a dedicated track vehicle. I'm doing 2 track events this year: Viper Days at VIR in late July and at Road America in early August. I am currently running the EBC green (front) and stock pads (rear) on the street. Prior to the VIR event, I will replace my front rotors with Stop-Tech Aero Rotors, and put Porterfield R4 pads on all 4 wheels. (I've used the R4's before; I'm happy with them and have no reason to switch. There are other options.) I will also install stainless steel brake lines, front and rear, and also air deflectors and Speed Bleeders. And replace the brake fluid with Motul.
I'll leave the pads and rotors on the car for the 2-3 weeks between VIR and Road America. Once I'm done with Road America, I'll reinstall the EBC pads and stock rotors. (The air deflectors can stay on the car; they won't get in the way.) Doing it this way, there will be no reason to turn the rotors or anything, since I'll just be returning the system to what it was before I went "racing." This, of course, is a somewhat involved solution, and between pads, rotors and lines, we're talking over $1,000.
My 2-cents...