for what?seems like I would need two of the batten,
That's a square area just over 7 ft on each side.the size of the boarding will be 50 sqr ft.
One of these would be plenty: https://www.screwfix.com/p/lap-bc-a60-led-light-bulb-806lm-7-3w-5-pack/310pp
in one of these: https://www.screwfix.com/p/angled-ho-batten-lamp-holder-light-fitting-bc-2-52-/1801d