Firstly welcome to the GTD world.
To provide some guidelines, a couple of questions back to you. 1) How do you get to/communicate with the 4 vendors? 2) What is the frequency of contact per vendor? 3) How important is the information you are trying to archive/file? 4) What is the information that you are looking to archive/file? 5) Do you have authority to remove information from the vendors site?
Presuming it's primarily driving (100km = (approx) 62 miles) and the information is critical for you job plus you have the OK to remove information, I would set up a in-car system that is transferred to your "home base" either daily or weekly. Given that it's 4 vendors ... 4 containers of appropriate size would work during transportation. Label then Vendor 1 etc and place the appropriate vendors information in-side. Then at home transfer the information to a filing cabinet (set up as per the car system so you're not double working the information).