I sell physical products- architectural materials. 

A contractor (eg. John Smith at ABC Contractors) will contact me and place an order, and ask me to deliver the product to the factory he uses (eg; Joe Bloggs Factory).

In this sort of situation, how do I specify the delivery address in the Sales Order (or in the Quotation).? At the moment, I have to copy and paste and enter the details manually.

Is there a way to add a contact look-up field, which will fill in the contact's name, the company name, and the address? Then, when we export a PDF, the details are displayed in the delivery address fields.

It seems like a simple thing to do, but I have no idea how to set up. 

I look forward to your ideas!