I had a whole house fan and two swamp coolers in New Mexico.

The whole house fan was good on cool nights or especially good at opening the kitchen window and evacuating cooking smells if you were frying something up. Overall I used the swamp coolers on fan only mode more than the whole house fan.

If I were retrofitting a house here in the Denver area for cooling I would go with a big swamp cooler in an existing window or easy wall to cut a hole in. I would have done that, but I am in a rental... So I just sweat and use a fan, natures evaporative cooling I suppose.

They also make LARGE evacuation fans that fir into a window, which may be an option for you? http://www.air-n-water.com/product/9166D.html