Sounds like this is your first grow, LED lights are measured in nanometers you want 420 blue and 660 red. 25% blue and 75% red will give your plant everything it needs.
When it comes to floros or hid then it is measured in Kelvin, 3000K is like the 660nm leds produce, 6500K is like the 420nm leds produce. but many more colors combined to make light we can see.
It really doesn't matter, if this is your first grow and you going small, get a 250 HPS. That will veg and flower a couple small plants better then LED's would.
Larger grow? Go 400w get ballast that runs both MH and HPS
trick to producing a decent crop indoors isn't necessarily the light. Its all about exposure and penetration of the light. bend your plants sideways so the shoots get more light = more bud.
SCROG is what gets the buds. (using a screen) that's the only way you will get a harvest that's worth growing with leds.
good luck