Likely your S2000 is in SSM class-wise. Basically the charger puts you there and all the other stuff you mentioned is allowed there. Your interior needs to be intact (seats are ok) incl. carpets since it is a `Street`class.
Your helmet needs to be Snell-approved (DOT approved is not adequate according to our insurance). M2005 or SA2005 or newer. There are a couple of European helmet stds that are also acceptable in case you happen to have one of them (rare) ... There is a list of those acceptable stds in the rules btw.
The club has 4 loaner helmets.
Reijo