As you can see, I am trying to do the same thing.
customize a more powerful cooler since my dell is keep getting overheated, it gets poor performance when it's fully loaded.
after finishing with the fans and boxes, I realized I cant get the Power Supply Unit to work, without a motherboard. Can someone tell me how to do it? use the PUS without the motherboard? thank you very much, I have a standard ATX Power Supply from my old Pentium 3 desktop.