Brett, the slang name or tech name for these type fans is "muffin" fans. Try, Amazon, Google, E-Bay, Newark Electronics, McMaster Carr, W.W.Graingers, MS Supply, etc. All those places sell them - they are readily available. The smaller, cheaper they are the more "hi-pitch" whine they make, they can get quite annoying... You can order guards and power cords to speed the install. Be careful with the 120 VAC versions, they can pose a shock risk depending on installation method. I would install a 12 VDC fan.