Actually, Goku said "a saiyan that has ascended past a super sayian, or Super Saiyan 2". Nothing like that has been said of Raikage's lightning armor, only you seeing him fully charge his aura to better counter Sasuke and calling it v2.
And there are more things to it than just hair standing up. There is an increase in power past their SS1 cap and it is balanced with speed. They become even more aggressive and cold. Plus, their super saiyan aura has electricity sparking around them.