In the middle of renovation and urgent help requested.

Open living room 20' x 20' living room area not including adjoining open spaces. Ceiling height is 20 feet. I want to buy ring chandelier like camino by RH. Hanging height 7-8 feet from floor. What should be the diameter/size of the chandelier. should i go for RH camino chandelier 63" or 50"?

https://www.restorationhardware.com/catalog/product/product.jsp?productId=prod2111630&categoryId=cat5700042

https://www.restorationhardware.com/catalog/product/product.jsp?productId=prod2111631&categoryId=cat5700042

What should be location of chandelier? center of the room (center line is where the red chandelier is behind in the dining room) or not center of the room but roughly above coffee table?