i assume those are 50w each, so you'd want a 320w meanwell, likely... hate to guess, though. you'd have to look at what is inside the unit for a better idea. it'll have all the important information listed.
is the flicker only seen through camera or with your eye too? might want to try to troubleshoot what part is broken too. it coudl be the actualy COB LEDs. could test the driver in another one or vice versa.