Dimming isn't a luxury is allowing you to not run your driver's at 100% for that 1050ma. 3500k is what you want if your using the same fixture for veg and flower.
Also I'm using 4 CXB3590S on a 185c-1400 driver in a 2.5x2ft setup. 2 COB per heatsink passive cooled and the hottest spot I've seen...