[Ryan.]

I'm occupied with projects right now but I think both of your ideas are possible.

The save/restore system essentially exists in QOL for its /skaterboy command. Players are respawned and all their previous loot is returned to them (including ammo). It's just a matter of writing the loot to a file and allowing it be loaded with a command. QOL doesn't save non-player entities though so all unequipped items, med-boxes and supply drops would be lost.

The second plugin sounds trivial to implement using SDKHooks. Hook item_inventory_box's spawn and then call SetEntityModel. If you're comfortable modifying server.dll this may be a relatively simple first plugin to build.