want to make this perfect

ok this is my fourth grow im coming up on now. i want to make this room as close to perfect as i possibly can.... afford lol. i currently have 2 400w mh/hps lights i grow in fox farm soil with three gal pots cuz im sure ill destroy something in hydro lol. now im moving my gro to a smaller room in my basement it is 7x5x7. previously this is how i grew, now i want it all to be right cuz i plan on spending the money on seeds finally for that size room and size of lights what would be suitable as far as exhaust and intake cfm, the amount of plants that would best suit that size room, how much of a difference will co2 make during my flowering stage would an environmental controller be necessary or just a waste of money? so basically anything you can answer will be greatly appreciated if im too vague on anything please let me know cuz i really want to get this right thanks everyone.

Wow , you did three grows and you can't answer your own questions ?
You should have seen how much they grow and the kind of ventilation you need for YOUR grow.

Well ive never set up ventilation so I'm really lost on that and I have some basic ideas but like I said I want this to be as close to perfect as I can get it so I don't really wanna just run out and buy a bunch of stuff that maybe useless so any feedback please

2x600W or one more 400W will cover most of the room and leave you a little space to move around. With low power lights like 400's, a scrog is probably the best bet. The 400W wont penetrate morethan about 18in or so.
The most effective cooling involves two fan circuits. One to cool the lights and one to ventilate via the filter. An 8in Vortex should cool the lights well and a 6in should ventilate the room. Match the filter to the fan's CFM rating. Buy a quality filter like Mountain Air or Phresh,etc. Can Fans work, but don't last long.
Start with these parts and run 5 or 6 cycles before you even think about adding co2. You need to have the room really dialed in first. I think an environmental controller is unnecessary in your application. Hell, I run 10 lights and don't have a need for one. A few timers and that's it. I'm a bit of a more hands on type. Seems to me full automation would take all the fun out of the grow anyway.
Hope this helps,
Fred

Great post thanks Fred I'll definatly be getting another 400 w and I have some t5 dual bulb SET ups that I plan to mount on the walls how many plants would be suitable for this size room and light total it will be 3 400 watt lights and 4 dual t5 lights through out the entire grow and does using the co2 really increase ur harvest 60% I heard that but not sure If that's true

The amount of plants depends on if you have a veg room. Takes a while to get large plants. They're not really suited to 400's though.
Lots of setups would do well in there. A 3x6 table with SOG with 30 or so small plants and no veg time.
An 8-12 plant Scrog would also work well. You can veg them in there under the screen pretty quickly. It would also eliminate the veg room and side lighting.
What ever you do, don't stop reading or asking questions. Soon you'll be pulling 25-30 bags per cycle with that room. Maybe more than that.

Bad pun alert. 60% increase with Co2? Sounds like a pipe dream!
If every aspect of your room is PERFECT, using Co2 may add 20% or so to the bottom line. Did for me anyway. Although perfect is not a word I'd use to describe my rooms. I'm pretty lazy.
Fred

ok well ive been online researching scrog grow setups since about 9pm it is now 6am. i think i have read and seen enough for that to make my mind up on how i will try this next grow. SCROG IT IS!!! the yields people are getting is ridiculous. im thinking about the strain now i cant decide between ak-47, northern lights, and a landrace strain malawi gold all from highgrade-seeds.com im only going with them because a couple of local growing friends use them and swear by them so ill give them a shot. any advice on the strain types, what strain would suit a scrog grow best please check out highgrade seeds and let me know, also do you think that 5 plants would be enough for a 3x6 table? or should i go bigger for that size?

5 plants is enough. Even 1 is enough if you veg it long enough in a big enough pot. I suggest 9 to cut down on veg and decrease turnaround times. 5 gallon grow bags would be ideal here, their gonna get pretty big to fill that screen. A 32"x 84" screen would leave room to work if you're not too fat. Any wider and you can't reach the back wall.
AK-47 or NL5 will scrog well when topped frequently. I've grown both, different seed vendor though. I tend to stick with the original breeders. costs more but you know what you're getting. They'll both be easier and yield better than Malawi. NL5 can be a bit sensitive to nutes, so be careful if you go that route.
Fred

Ok what seed bank would u recommend I've looked on nirvana, high-grade, bcseedking and a few others. Bcseedking had some really nice strains but the prices where higher then mostly everywhere I looked and about the amount of plants used I figured if I used less plants it would be better incase any happen to be males so they can be pulled easier Fred ur my new mentor show me the way lol and thanks for all the feedback

Attitude seed bank came through for me, stealth shipping to the usa and they carry all the major breeders

Attitude. Never had a prob with them. Pay the extra for guaranteed shipping.
Fred