2 600's over 1 1K for sure, but honestly, that is exactly what I have been using for a 4x8 area (32 sq ft) which is less than Leon's 6x6 area (36 sq ft) and I am upgrading to 2 1k's for that 32 sq ft area. Besides Woody's science based minimum 5k and, better, 10K lumens/sq ft for optimum...