I have always used a hole in the ceiling for venting, as it normaly vent heat, with a high temp fan that comes on when the plant height get to a set point.
The in take is used to pressureize the room due to the exust normal drag.
If you note my intake box , with light blockers, filters.
You kill a few birds at the same time, clean air in, pollen stoped with the hepa filter and positive pressure to push out any leaks in the door jam, seals.
It has worked for decades, with out failure.
The only problem was a person came with mites from his crop. You can also vent to the grow room and scavange the co2. This has a added effect that the clone section is kept at around 80 d.f.
Note with 2 kw of lamps your going to need a good vent fan,, and a good controler , attic vent works great.
I never had much luck using hps for bloom in test at a few sites. Try them both and see what happens. YOU will be suppised , with tight firmer, better weight.