I've gone to the last 5 COCOA events at WSIR. Loads of fun, you won't regret it. Cars vary from Cobras (of course) to Mustangs ( GT350s mostly) to almost anything else. I have seen GT40s, NASCAR trucks, etc. All Ford powered.
This is not a track event in the sense that you are running for times. This is a fun event. That said, the race group gets around the track pretty fast. You need to be good to run the group.
Great instruction is available, in the classroom and on track. Usually Danny McKeever is there, owner and head instructor of Fast Lane driver school at WSIR. I always get some instruction from him when I have the chance. He will ride with you in your car and help you.
Sadly, I will miss this event because my Cobra is apart, but I will be back at the October event.