new growing advise plz asap

thinking about purchasing a supercloset 2.0 because i do not know how to set nothing up and do not have the time the specs are
Dimension: 61"h x 15"w x 24"d
i will have c02 system
250 hps or 400 hps
8 plants 4 northern lights 4 pineapple express
Reverse Osmosis Water Filter

my question is with the specs should i get the 250 hps or 400 hps i'm new to this and would anybody be able to give me a rough est of expect yield total even if your guessin around average
if you know about the super closet everything is comes fans etc etc