I don't exactly know what you mean. Do you want the equipment to be 'edited' in-game? I'm assuming not..?
I would create a class that would hold all the information neccessary. This information would include Name, Price, Attack/Defense, MagicalAttack/Defence, etc. Then I would add each piece of armor to an array. Your inventory would be another Array. It would be pretty simple to get items from the masterequipmentarray, and add them to your inventory. Equipment would have to be done a little differently, but shouldn't be difficult.
Note: The Windows Forms section is probably not the best place to post this particular question.