Advice needed (Outtake CFM, Carbon filter, and HID light)

Hi, I need some advice. Im not getting the exact answers that im looking for through google so here goes!

I have a tent (4' Long, 3.5' Wide, 6' Tall) It is located in a basement with cool air in the summer, and can get really cool in the winter months. The summer averages 70 degrees, and the winter depends on how much heat i give the room, so thats not an issue.

The tent is up against a wall and will be venting into the next room "point blank" i guess you could say.

For this size tent and setup, what HPS light wattage would you recommend? 400w or 600w?
I also have the ability to dedicate a 180 CFM duct fan to the light for ventilation. Would this be enough? or even necessary?

I know the tent is about 84 cubic feet. Divided by 5 thats 16.8 CFM for a 5 minute exhaust correct? Or am i wayyyy off?
But i read quite a bit of people saying for tents this size, that they use 400+ CFM filters and inline fans.

So… what do you think?

What size (CFM wise) carbon filter should i use for this size tent? and what CFM inline should i get?
Keep in mind i want to be preventative for the future in case i get something with some serious stank to it

Would it be better to hook up the cool tube, and carbon filter to the one inline fan for exhaust?

Thank you for your input!

/bu-bu-bump

if you can afford a 600 now, get it. You will soon want even more, we all do. Bottom line more light = more bud. You got the cool temp for it,.. hook your new 600 up for a bit and see how hot it gets man, then worry about venting, if needed. If you're not adding co2, and temps aren't an issue (lucky) just run a neg vacuum through a carbon filter and no one will smell a thing