For inventory system, check my RPG Elements pack. As for the inventory menu itself (item management and stuff), you'd have to create it on your own, as I have not made available my menu systems in general yet. But in general, it is possible to switch between menus, provided you code the appropriately.
This map system was inspired by all the 2D metroid/castlevania games, as well as map systems from several other games, Zero Mission included. So yes, you should be able to make something in the scope and size of Zero Mission.