question about number of plants

My room is 8x3x6ft high im wondrring how many plants do you think i can fit in there at once and do you think i should use 2 400w hid or two 8bulb t5hos.

4 plants in 3 gal smart pots with two 400 watt mh for vegging and two 400 watt hps for flowering.

Most def 2 400s n how many is more like how big you wanna veg em