Do you mean the physical files (such as pdf) or just on the line items from the quote items table? If its just the quote items table you could amend the view used by the search screen for quotes (although this is not recommended).

Something like changing vQuoteOppos to below should do it:

SELECT Quotes.*, vQuoteOpportunity.*, QuoteItems.* FROM Quotes, vQuoteOpportunity, QuoteItems WHERE Quot_OpportunityID = Oppo_OpportunityID AND Quot_Deleted IS NULL

This will then expose the quote item fields to be added to the Quote Search Box.