correct size carbon filter for 4x4x7 grow tent?

im looking to filter the smell out of a grow tent, and i'm trying to wrap my mind around the fan and carbon filter needed to do this.

now, i'm looking at the Can33 can-filter, heres a link: http://www.4hydroponics.com/grow_room/can-filters.asp

i'm using 6" ducting, so this is the smallest they sell in the 6" range

in addition, i'm also looking for a fan, and im not sure what CFM i'm going to need, or whether or not i can survive with a generic ducting fan from lowes; i think its kind of similar to one of these:

http://www.4hydroponics.com/grow_room/ecoPlusDuctBooster.asp

they are much cheaper than the Can fans and the other duct fans; but i'm not sure they push sufficient air, i'm going to use one of these to air cool my reflector, since i think it has sufficient power to pull air across a bulb, but i dont think that it has enough to push air through a carbon filter.

anyone who has set up a system like this, can you help?

and what company makes good fans? Carbon filters?

i was focusing on can-filters and fans because they seem to have a large market presence, but i've never seen one in person, so couldnt vouch for their quality

Lol, i hate to keep adding on to this, but what sort of hanging system for a reflector would anyone recommend? i'm looking for something adjustable to make sure my reflector is in the right position at all times

might as well get all of my questions out of the way at once, right? lol...