Take a look at sanlight austria, I don't know if they ship to america, but you can see a huge difference in Umol and outcome, if you want to build your own leds use 3W Laser LED's Osram is the number one supporter, these leds do a much better job, then everything else one the market, don't waste you money on 1 or 2ws those are just for normal room enlightment.. COBs can be good, but choose wisely and make some research about them, for me it's better to mix the spectrum on your own. Sanlight fixtures have a like 70% red outcome in the range up to 730nm which is very good for flower. But are lacking a bit in the blue spectrum.. I think the lamps will get better each time, I see virtual sunsets coming with timers and dimmers, soon you can create a very close enviroment as natural for your plants, but sunlight has to be understood much more. It's more then just the light we see, it's basically information in itself. Be well Brothers.