I started with a trip to Lowe's Home Improvement Center, as always. They have a decent selection of aluminum stock but their prices are high. The one-eighth inch by two inch angle stock used for the corners of the case cost $18 for an eight foot length! The two inch wide flat stock was about $2 per foot. The total cost of the aluminum used in this project exceeded $125. Check with a local metal supply store if there's one in your area. You could pay a LOT less for aluminum than Lowe's charges. My only goal for this project was the total absence of visible fasteners. That means no screws, rivets, etc.
The exterior would be completely smooth and very stark-looking. The CDROM drive and even the power and reset buttons would be hidden inside the case. The keylock and protruding heatpipes are the only exterior features.