Ron, it is difficult to find ready to buy helmets here in Phoenix, but Summit Racing sells them and delivers fast. Here is Summit's Bell helmet page: 
http://www.summitracing.com/search/?...0Helmets&dds=1
I have this one: 
http://www.bellracing.com/public/ind...ct/detail/130/ but it is good for only 10 years for SFI dating. Year dating is every 5th year, so mine is 2000 and theoretically is expired but I'll bet it's OK for Speed World.
AZ bob