If you emailed your local computer shop, a small one though, not a big chain store, they will usually assemble a computer for you if you give them a list of parts. I designed one and emailed the specs I'd like to a nearby prefab and they purchased the custom parts and built it themselves. It's the best way to build a computer
There's only one computer shop I know in washington and that's Bear Computers, which Gabe Newell, basically the guy who managed the Half-life games, got his computer from there.
http://www.bearcomputer.com/
Give them the specs you want, which we can help you with

and they will make it for you.