pico-PSU compatable and must support one half-height expansion slot and one 3.5" hard drive. No bigger than you really need to fit the hardware
found
http://www.minicase.net/product_E-N3.html
but no expansion slot
http://www.streacom.com/products/f7c-chassis/
fits the bill but I can't find it for sale anywhere and the cd slot is not needed.