Add abilty to create a customer quote on a php website app

I have an existing website with a php app and mysql database. We are a construction company and use this website to track customer information and installation dates. I have existing search functionality and am able to open a window with all the customer's information. I want to add the ability to create a quote for a customer, and generate a pdf of the quote. This is kind of like a shopping cart on a website, except that I don't need to be able to process any payments online. One customer can have multiple rooms, each room can have multiple quotes, and each quote has multiple items in it. I'm not very picky at all on how it looks. I created something using Access as a front end to the mySql tables to help me figure out in my mind what I'm looking for. I attached some screenshots and notes, but remember the look doesn't really matter to me, I'm MUCH more concerned about it being intuitive to use. Please let me know if anything's not clear and I'll clarify as needed.