I'm with Dutch Pimp, you don't have a tent.. with 4 x 600 watt lights, you have an oven. You're also planning to pack WAY too many plants in it.. Space between the plants and ventilation is a good thing. Depending on how long you veg.. 6 plants could fill this space up after they stretch and spread out during the first 3 weeks of flower.

Good luck.

Farmer Rich