I thought when I saw the picture that you would probably get a warm and fuzzy feeling.
Amazing what a cheap little box fan can do. Heat in electronic components seems always to be a problem. We had electronics in enclosures in areas that reached 135 degrees so you can imagine what temperatures the electronics inside were running at.
I don't have a pic, but I bought everything from a place called »www.coolerguys.com/
The power converter is called a CS 110v AC to 12v DC Item # 840556029977 Description: Power Supply with 4 Pin Molex Adapter
It was $14.95 a couple years ago. Just looked it up on their website & same price still. It has two Molex outlets, so it can power 2 fans.
If you search for "120mm AC fan" on their site, you'll see a selection of fans powered by AC so you can skip the adapter. Be sure to add the cord to the fan- they have a couple length options.