hey man,
good start; nice space. but i'm confused (or stoned
)- are you going to grow AND flower in that one room? obv you will need a seperate space to flower 12/12 away from cloning and veg.
If it's a
flower area...
I've done a cpl grows in small closets like that. the 400w will be enuff if you mylar up the walls. heat will be yer big concern, also ventilation!! if you have a ducted exhaust (fart fan) from the ceiling, then you might be able to bump up the wattage.
have never grown SS- is yers Sensi seeds? those are potent and fast but stinky too. you might need some filters and air treatment.
good luck!!