Transport företag. Which a-kassa and union?

Hi,
I am sorry if I put that topic in wrong section.
The question is, I have a friend who has his own företag (handels bolaget) - in the future he will change on aktie-bolaget. He is C+E lastbilhaufför.
Right now he is in standard alfa-kassan. Is there any better a-kassan especially for transport section?
And what about the unions? Which would be best for him?

Thanks in advance.