Update: all up and running going on week two with Boveda 69's lining the bottom edge (added more after the pic, so about twenty total) and 4 small Xikar gel jars with the Xikar brand PG Juice in them (I already had this stuff and have had good luck in my humidors with them). Last I checked I got readings of 65% bottom corner, 64% two boxes up, and 63% on top tray (high-middle).
Will keep in mind your suggestions for Beads or Kitty Litter for this much space (150 qt.) but so far so good.
Overall real happy with the results. Will be adding a few more boxes today. Great seal, tons of space, and a terrific aroma when opened.