Some years ago, I bought a barebones MSI laptop from AVADirect. It's a pretty good little machine, and I hope to get it back some day.
Anyway, I just checked, and they are still selling barebones laptops. I have to admit that their customer service leaves a bit to be desired, though. My laptop came missing the metal piece that holds the harddrive in, and I had to argue with them for a bit before they finally got one sent to me. Otherwise, they will install the parts (assuming you bought the parts from them) and test it for free.