Okay, so a lightweight SecureIt Agile 52 (and perhaps a 40 stacked on top) is out. If you were looking for a locker and were not concerned about cost, that would have been my first recommendation. I love their cradle grid system, but they are pricey. Also might not be big enough, depending on what you consider gear. Does that include battle belt, plate carrier, etc? Or just rifles, pistols, and magazines?
Vaultek also has a couple modern options (RS200i & RS500i), but they are even more expensive...and I have seen too many issues with their containers over the years to have much confidence in anything they make.
Tractor Supply and Walmart have a wide range of lower end cabinets from folks like Stack-On. That's probably where I would look...but curious what other folks suggest.