Greg, get NEW track oriented front brake pads, make sure the rears are in very good shape, good rotors, switch to ATE Super Blue(IPS Stocks it) and your good to go.
Shawn puts on a good event, you'll be fine if you follow the rules and don't push any more than you feel safe to. Nelson doesn't have a LOT of runoff room but you won't exactly be doing 127mph either and unless your being stupid you won't be going off track your first time out likely anyway.
If your still not sure, go up there and ride along with some people to see what it's like, I can tell you it's a blast and safer than the drive itself to and from the track.