My next idea is a crest that hangs on the wall.
It's just longer than a foot tall, 10 inches wide, and 3 inches deep.
The pink box is the motherboard, mounted crest-side, ports facing down. The green boxes are fans, one in and one out; though they may not provide the best ventilation route (heat rises). The gray box is the slim slot load DVD drive, and the purple box is the HDD. I've chosen to use a pico power supply. They seem ideal for this application.
This shows the slight bend in the crest itself.
I was thinking hammered sheet metal for the crest itself, but I do not know if our judges are blacksmiths of olde (or know one).
It's meant to be wall mounted from the backside with the cords hanging out of the bottom of the crest.
The paint job was inspired by the "Shield of the Cleansing Flame" of Shadowbane.
Motherboard - $0.00
Ram - $0.00
HDD - $0.00
Sheet Metal - $???.??
Slot Load DVD Drive - $70.00
50mm fans - $5.00 (x2 = $10.00)
PS. If the budget allows, lighting the fire with LEDs would be fantastic.