4x4x6 tent 400 hps please critic!!!!

Me and my dad are building and growing my first indoor and just have a few questions about growing in a tent in a 12x12x8 room I would like to build a sea of green in my room.Where do I spend money and when can i make or build something? My dad is there all the time what should i have him check when Im not there(like,temp,humidity,ect)? and what should he not touch? I have a 400w hps/mh, what kind of light for veg should i build or buy? The site growace.com has good deals it looks like but should i go that way?does my ventulation with the ac ducted to it oscalating fan blowing the cold air from the vent around and a little fan pulling the air out? If i got a bigger light whats the best way to vent it? i don t care about smell live in the middle of nowhere! please look at and critic? if want more pics let know of what Thank you The pics start as you walk in the room the 4 plants i want to bud out in the tent under the 400w for right now critic critic this please keep in mind i like to build things!!

i dont know what climate your in but it looks like the mountains or something. just watch your temps and even that 400 will kick heat without cooling or exhaust/ just keep an eye on it. a 600 would probably be ideal for a scrog in that 4x4 but i would just stick to to 400 if you already have it. its def enough for the 4 plants you have already. MH for veg. HPS for flower. thats how most of us do it anyways. good luck man.