Motorcycle shops will not carry SA helmets unless you special order them I believe. You have to go to a race shop to find SA rated helmets.

The sticker should be underneath the lining somewhere inside the helmet.

Everyone has their personal tastes though I love a close face helmet cause my sunglasses slip down my nose on hot summer days. Plus I wear contacts and need the block the wind. I leave my visor open about 1/2" everytime I run. I never fully shut it.

The HPDE school I attended with NASA back in 2002 only required M2000 helmets or better. You could fork out the extra money for an SA helmet, but check the rules. HPDEs also do not require roll bars or extinguishers until you get to Intermediate schools I believe.