Corsair 900D can fit a 480 on top, but for that, be prepared for a monster case, as any will be to mount a 480 internally. You'll need a full tower to mount an e-atx mobo anyways. It'll also fit a 360 up front, I don't see any reason a 360 wouldn't work for a cpu, no matter the OC. You'll hit voltage limits long before maxing a 360 since that'll be the only thing on that loop.
Apart from custom orders, I don't think I've ever seen a commercially sold case that'll mount 2x480 internally.