I have a 'Cool Breeze' reflector with a 400watt bulb, and I just use a tabletop Vornado fan blowing sort of into one end of it, and I tell you it is cool enough for me to just lay my face on it if I wanted to, lol. BUT, I have an attic vent above where I let my hot exhaust air go.

So *IF* the fans purpose is JUST for cooling the reflector hood, then you may be able to use a normal fan.

But if you need to force that hot air OUT (which it sounds like you would!), then a fan and ducting is obviously better.