"find this for me" plug in

I have an e-commerce store that is for antiques and collectibles. Many collectors only collect certain patterns. My question is this:

Is there a plug in out there where a customer can create a list of items, or a single item, from a certain pattern or category that they are looking for? And then can be automatically emailed when/if that product is added to my inventory? Sort of a wishlist, but not for products already in my inventory…a wishlist for items they are actively searching for?
To further clarify, here is an example: a customer is collecting a certain pattern of dishes, but are missing a bowl. They can create a “find this for me” list, requesting the bowl. If I find the bowl and add it to my inventory, they are emailed so they are aware that I have it in stock.
Anything out there like that?
Thanks for any info/ideas!