Here is my problem...

We have several components that we use, that have multiple variants, and I need a way to assign the component to the end product whilst being able to track what variant was used. 

Actual example, I want to add a 1TB Hard Drive to a computer. My component is a 1TB Hard Drive the product is the Computer and my variant will be a 1TB HDD from Seagate, a 1TB HDD from WD and a 1TB HDD from Toshiba. 

As far as the product BOM is concerned it does not matter what drive I use, but I do need to have them as separate inventory line items, and if I were trying to use 10 of them, I would want to use all the same brand.