I think what is being described is something like
<---FAN---(ducting)---[AIRCOOLED HOOD--<--]---<---(air sucked into box)
I have used a 440cfm EcoPlus inline blower with a 600 watter. Powerful, but I don't think it overkill. Plus, I'm pretty sure I can put another light on this fan. It is NOT quiet. Although building a box around the fan helped a lot.