I have that same cabinet, with 2lbs of Shilala's beads in it. I have a bag on each shelf, one in behind the drawers and a couple extra spread about on the shelves. I used to have a Humi-care XG1000 in the bottom, but it became pointless after moving the cab into the basement. It holds a rock steady 68-69% now. With XG1000, it was over humidifying the cabinet.
As for fans, I haven't bothered. I open the door at least once a day to grab a cigar. That's my air circulation.