I really like the Bell S2R, but I think it is SA2005. I bought a new Simpson Superbandit. I like that one too. It is SA2010. The Bell is more open, which makes it easier to see any gauges in the car, but I find I like the Simpson since I moved most of my gauges up.
The SA part is for fire resistant liner. Good idea. You can get these helmets all over. I got mine at TheCarShopInc from Tim Ryherd. He is a good person to deal with and good prices. A racer and he sponsors our Heartland Stock Superstock series. Worth a look.
http://www.carshopinc.com/index.php