wondering which space is better

The attic is 3 1/2 ft tall, 6ft long and 4 ft wide and has alot of ventilation. would be the preferable spot but is it tall enough? Only planning on 2-3 plants using a 250-400 hps light to flower. The closet space seems the easier of the 2 but worried about ventilation and it isnt very discreet.

3 1/2 feet doesn't leave you much to work with if you take into consideration that whatever you use to hold the plant will have some vertical height, as well as the light above the plant eating up space. you would be looking at probably less than a 2 foot tall plant when all is said and done. how much yield are you aiming for?