Sal,
PDA/NASA will have an HPDE event at Thunderbolt Raceway next year, It may or may not happen before the SAAC event. If it is scheduled before SAAC I suggest you sign up when PDA posts the date. If you are lucky enough to get some tracktime at Thunderbolt you will be way ahead of the SAAC regulars as far as knowing the track.
All the advise posted so far by Jamo and others is right on especially Bill's advise about regular street tires for first timers. So many inexperienced guys (myself included) made the mistake of doing their first track event on Race tires.(big mistake) they hold the corners so well they give you a false sense of security and they don't give up until you are driving well over your head as far as being able to control the car. Better to spin out at 50 MPH rather than 90 mph in a corner when you lose it.
Keep checking the PDA site for the 2008 schedule of schools, if they don't have a school at Thunderbolt before SAAC you can always sign up for a school at Watkins Glen or Lime Rock Park (if your car is quiet enough, most Cobras are not).
RD
http://www.pdadrivingschool.com/