Light Help for 1.5ft Square closet grow!

Hello!
Ive been researching and reading around for AGES trying to understand what lights are good for what stages of growth, size of grow box etc.

As i understand it Cannabis prefers 50000Lux (50000 Lumen per Meter Square)
And all the equations i see done are calculated in Metre squared.

I also understand that the Light spectrum changes from Veg to Bud. And that they need 4-6 weeks 24/7 of 6400k [Blue] spectrum light (Im not sure what type of light would be best) and 12 weeks of 12 on 12 off with 2700k [red] Spectrum for Bud (i heard a High Pressure Sodium light will produce this best)

Am i correct on what i understand so far? And if so what Bulb would be best for the veg stage?

The main problem is the lighting wattage with the size of the closet. Its 1.5 FOOT square by 5 foot high.
And according to the sight below a 400W HPS would be perfect for 1x1 Meter (50000 Lumens). Would that burn or damage plants in a smaller area of 1.5x1.5 FOOT



Cannabis Lighting Types and Intensities says:
400W HPS 50000 Lumen will produce 50000 Lumens 1 Meter sqaure and 33300 on 1.5 Meter Square

Im sorry if im dangerously incorrect and i hope i cant get some help soon!
Thanks in advance (hope this is the correct place to post)