What ventilation to get?

Hey RIU, I'm in route to starting my first grow. I finally figured what lights I will be using. I will be getting the 400w 3000k Vero cob set from Timber... and I will be doing 3 to 4 plants in a 3x3 tent.
so I guess my question is... what kind of ventilation will I need for this setup. I know a clip on fan or two... but what else do I need in my shopping list when It comes to air flow? Is a intake or exhaust needed in a cob grow tent since Temps stay low? Also i know i want a 3x3 tent... but which brand 3x3 tent should i get... without getting a Gorilla brand (don't want to pay that much for a tent.) Sorry for newbie like questions. thanks in advance.

Hi There

I use similar size tent for all my grows, for my experience, i used two 15w clip on fans to clip on two poles of my tent diagonally to make sure the top of my plants get constant air flow to avoid heat building up through out the whole grow. For ventilation, because my city is normally very hot and humid during summer so I used a 150w vent fan to kinda "push" the heat that produced by my 600w hps. The fan was placed inside the tent so it could make the humidity in my tent lower to an acceptable level. At flowering stage I would place the vent fan outside of the tent and connect my hps with an air filter so my vent fan can suck the hot air out of the tent.

Hope this can help you, sorry for my bad English, have a nice grow!