I have a short commute but I carry as much on my bike as I would in the trunk of a car. I also ride an Xtracycle so I can carry all I want. Today it was two teenage boys, not very far though. They weighed a ton.
Your commute is so long you might want to go to a Cateye light. They have one that is solar powered and is supposed to be great. Depending on your climate you might want to add some packable rain pants, you just throw on over your jeans. Wind proof, water proof.
Glad your making the commitment to commuting. Welcome back.