Painting Engine Bay

I was in this exact position. The paint under the battery tray was etched away by the battery acid, but the rest of the engine bay was in pretty decent shape. I was gonna just try and do the inner fender below the battery tray, but after discussing it with my body man, he told me I would later regret it if I didn't paint the entire bay while the engine was out. I'm glad I went with his recommendation, as now I am also changing the entire color of the car to this: