Inventory Structure

I've recently begun work on a large-scale project using and learning Torque along the way. To begin, I need some form of inventory that is pretty much completely different from what is currently available in Torque. I'm used to Java/C++ programming, and the script language with datablocks is still new to me. However, I'd like to have a system which has an array/linked list of the actual Items (in my mind, Crossbow or HealthPack would be a subclass of Item) and then use their properties which all items would have to determine if the user has reached the maximum number of those items or not. However, Tim Newell's tutorial simply doesn't work right, and I still don't entirely understand if what I'd like to do is possible.

I simply want to make an inventory system which uses the actual item objects. How might I go about implementing this? I feel like I should be modifying the Item class in the engine to do this but I'm not sure how I would go about doing that.