You could try looking at my inventory for a basic idea. Be warned it is super complicated and I never did finish it. If you need help with any specific thing I can help you.
http://www.alice.org/community/showthread.php?t=6104
Good luck
Current Alice Projects
WaVE fps engine
Inventory-------- NEED HELP WITH MY INVENTORY!!!!!!!!!-----------------------
GTA Alice
My Website
http://teamamazingstudios.webs.com/
My Unity 3D Game
http://www.youtube.com/watch?v=7hd__0Yyf5U