Looking good. Regarding the PSU, a DC-ATX Converter might be interessting. With that you will "just" have another external PSU: HDPLEX-250W-Hi-Fi-DC-ATX-Converter (16V-24V Wide Range Voltage Input) & Amazon.com: Dell AC Power Adapter Charger For Dell J938H Laptop Notebook Computers (Flextronics Flat Version): Computers & Accessories That Converter should fit into the enclosure. Will give you a nice clean look. What kind of fan is in the front? 80mm? Maybe you can use a pice of cardboard to guide all the air to the GPU.