Definitely 120v plugs for the inside. Dedicating a reloading bench to one wall would be a wicked idea.
Food for thought on those who don't have heated spaces but want this to be heated (I'm a heat & frost insulator by trade). You could use utiladoor panels (urethane w/aluminum facing) around the outside, Rockwool and siding or polyiso board & siding with a space heater inside.
Another heating option would be to run electric heat trace with an insulated envelope. The electric underfloor heating mats that you install flooring over would be a good idea. May not fully heat it, but it would take the chill off your feet. Regardless, if its going into a unheated garage/shop and you plan on heating it, raise it off the slab a few inches and throw a bunch of rock wool underneath it so the slab doesn't cold bridge to the container, that would also help big time with humidity.