SOG lighting question please help :)

Im going to do a 8 plant sog in a cabinet thats 3.5 feet tall 4 feet wide 2.5 feet deep.

im gona have a 400 watt bulb at the top of the box. if i grow the plants 6 inches and start 12/12 they should get no bigger than 18-22 inches i was told. this light isnt to far/close to harm my plants is it?

 

i'll have 2 exhaust fans that are 4 inch each taking out old hair bringing in new air.

the TOP of the pots will be flush to the bottom of the cabinet giving me more grow room.

the light at the top would come down 4-5 inches.

i just wana know if this would give me enough grow room for all 8 plants and provide a decent sog yield if i 12/12 at 6-8 inches bring my plants max 2 feet. guessing there would be more or less 8 inches from the top of my plant to the light. i would have excellent air flow IMO

think this would work well?

 

also does anyone know for sure or have a link to a chart or something that would tell me when i start my 12/12 cycle how much more average growth to expect?

 

yeah i have holes at the bottom of the cab leading to another area. its actually gona be 10 plants now i have the room i believe. im gona 12/12 at 6 inches and if all goes well next time around ill increase it little by little.

im gona be using female seeds from nirvana. most likely gona use supergirl or wonderwoman. seems to be alot of good reviews on those for sog grows and work well for small plants. and at the same time im either gona grow ppp or medusa. medusa would give me a slightly smaller yield but the smoke is so nice.