help for my hat

[darkriders_p2p]

Ok I have my hat NPC and its basically finished from my point of view.But Now I want to add another part:
When I pick up the NPC I want it to enable only 3 hats (mine lets you use all of them).And I want to make it so only buying hats will allow you to wear more.I think I would just use arrays but not sure exactly how.It would be easy if I could use keydown and it will go through all the arrays that were equal to 1.Please help me on how I would go about this