I think you'll find most stuff from this year is available at GP4 Central.
With a scattering of other content, like Tobi's fantastic 2013 mod, found throughout these threads.
For helmets we have Excalibur's set, while there are another odd few scattered around, but Jose is the main man for helmets these days. Think you'll find most of his stuff over at GP4Forever.
Races: 163 - Wins: 23 - Pole Positions: 24 - Fastest Laps: 22
Season 9: Constructors' Champions