Dell XPS Notebook – Replace screen (order correct replacement part) and what is the name of the frame around the screen – can it be purchased separately?

I want to replace the screen on a Dell XPS 15 9520 laptop because most of the pixels are broken. How can I ensure that if I order a replacement screen, it's the right one and a genuine Dell product? They're supposed to have numbers, but I can't remove my screen until I can install the new one directly. The technical specifications don't specify anything specific:

XPS 15 9520 Setup and Specifications | Dell Germany

And does anyone know what the black frame is called that holds the front frame around the screen and the back of the case together, meaning both parts are held together? It's broken in my case, but I don't know what this part is called or whether I can buy it separately. Do I have to buy a whole new case, or can I buy the part separately?