Mass File Field Update

Hello All,
     Here is my situation, and hopefully this is the correct area in which to post it.  My company sells drums and percussion instruments from several different manufacturers.  We are currently trying to set up "item compare" capabilities on our website so customers can do just that, compare and contrast the features of multiple items.  However, in many instances, one instrument can hold multiple warranties depending on which part of the instrument may be defective or become damaged.  For instance, the wooden drum shell may be warranted for 3 years from manufacturers defects, while the metal hardware on the drum