Which is better for increased classification of Item Master Records, UDD or Item Supplemental Databa

We have a need to load a Parts Inventory into the Item Master to better track the value of the inventory. We are starting with the higher dollar items like motors and gearboxes. The motors need a better breakdown than the few Class Codes (PRP1-PRP0) in the Item Master (which are pretty much in use by our component and chemical items that are for production.). For example motors can be AC or DC, various volts, amps, shaft sizes, and mountings that help identify the motors and won't fit in the description. Then a different group of characteristics are used for