Well, Ive been reading it, that you only want to use one light=? Why=?.... you are moree flexible using 2 or 3 Lights. Because the Light spreads better, in that big space. And for the beginning you may Need just one light for the seedlings, and later you can switch second or third light.
I would go with 3x Spiderfarmer SF-2000, for flowering stage……
https://www.spider-farmer.com/collections/all/products/sf-2000-led-grow-light