Design my own case huh? Well...
* What size? Mid, Large, Small? ~ Full tower
* What color interior? What color outside? ~Silver or Black internal and external
* What material? ~ Aluminum, of course
* PSU Mounted Top or bottom? Bottom, or both
* How many 5.25" bays? Door? Mesh all them? Either an Antec 900 style 5.25" style or as few 5.25" bays as possible, maybe just one, so I can fit more fans.
* How many 3.5" bays? Hotswap any? Sideways mounted or normal? Side ways, no hotswap
* How many fans? What size fans? Fan configuration? 2-3 120/140mm front intake fans, 2 140mm/ 3 120mm top exhaust fans, 1 120/140mm rear fan, 1 140mm side fan over the GPU, 2 internal 120/140mm fans for a push pull on the HDD bays and front intake.
* MOBO Configuration? Inverted? Standard, removable
* Cable management? 1"+ space behind mobo tray and 800D-like cutouts
Basically an aluminum version of the Antec P190 with better cable management and a removeable mobo tray:
Or the Lian Li PC-A71 with these:
http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=130_158_711&products_id=28207
http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=130_387&products_id=24603
As you can see I have expensive taste...