Are you leaving room behind for ventilation? What function will this PC perform - does it need to game, be a silent HTPC etc?
Im planning to have this pc do gaming. I want intake through the front and exhaust through the back or top.
I was looking into building precisely the same thing; I spent e few months idly searching for the perfect case that took up only half of a space, only to realize I need to make one myself. So I'm stripping down an old tower, cutting it to fit, and fabricating some kind of decent looking face plate. If you find something let me know, it'll be great to see what you get.