Okay I'll throw this out there without any extra stuff we have been working on. Here is the basics of spawning in a ammo box that updates to the database. If you put more than 80-90 different items in it will error out and not spawn. eg. 100 m4a1 and 100 stanag mags would only count as 2 items. All of this is done in the dayz_server.pbo.
Go to your compile folder and in the script server_playerSync and server_updateNearbyObjects add the classname of the object that you want to update after tentstorage.
Eg for classname "USBasicAmmunitionBox"
} forEach nearestObjects [_pos, ["Car", "Helicopter", "Motorcycle", "Ship", "TentStorage","USBasicAmmunitionBox"], 10];
Add the classname to the table "deployable" and note the id number
So you do not delete the box with cleanup script. Make a new Survivor in the survivor table with a randon ass UID and set isdead to 0. (this will make it so if it is not used within X days it won't be cleaned up) This will vary server to server.
Note the ID of the survivor you created.
Now go to your instance_deployable table and insert a new entry. Leave id blank and make up some crazy UID for the UID field. Under owner ID put the ID (Not UID) of your created survivor. Worldspace explanatory. You can create an inventory or leave it blank. All other values are not needed. Create the entry.
Restart your server and it should spawn in like anything else.
I am not responsible for your crap not working or breaking your database. I have only tested this for a day on my server.
AGAIN BE CAREFUL WITH HOW MANY DIFFERENT ITEMS YOU PUT IN IT!!!!!
It will save to the db fine but when you restart the server it will error out on the overfilled box.