Ideally you will want to suck the heated and stinky air out of your space in 3-5 minutes time.
In your case you have a volume of 40 cu ft. So you would want at a min. a fan rated at 8CFM. So pretty much any type of fan is going to be able to handle this. You will need to decide if you will also run a filter on this system(for scent control). If you decide to do cooling of the lights too via a cool tube or what you had said earlier a cool air hood, you'll want to decide to have that in the same system as the exhaust or on it's own. Lots of good threads on different setups and configurations on here.
I would research types of fans on here and also in online stores.
The key thing you'll want to figure out is where will you draw the cool air from that will get sucked into your tent. And where will you exhaust the heat to. I see a lot of people on here with the tents and/ or closets have all the right gear. But what they end up doing is sucking in air from an adjacent room and dumping the heated air back in the same room thus progressively heating their space and rendering their venting system useless.
If you need some further help don't hesitate to ask. Lot's of experts on here that kick so much ass.