Rrrrowr!
Light and ventilation go hand in hand and you should actually consider them a single entity, if that makes sense (it will when you try to set up a grow).
You need a minimum amount of ventilation no matter what, but the ADDITIONAL air movement you need then depends on your lights.
I've never run one of those big CFLs but I have seen successful grows that have. IF you go flouro, be certain to train your plants to have a shallow, flat canopy. You should be able to exhaust the heat off that sucka with just a 4" duct booster fan.
If you have a total of about $300-$350 to spend on the light/ fan combo, consider a small HPS light. A 400watt with air cooled hood is ideal for a space that is about 3x3x6'high and you can vent it with a 6" duct booster fan. The fan is cheap but the light is expensive.
Bigger than that and you are looking at running a REAL blower, and those run $100 or more for just the fan.
Your results depend on your conditions and light. And as Cigs42 pointed out, plants grown with care and attention blow commercially-produced weed out of the water once you learn what you're doing.
Don't skimp on exhaust!
If you plan to go bigger later, get the better exhaust sytem set up now. It will save you having to replace it when you buy a larger light.