What's your budget like, and are you into modifying the case? One possibility is the Antec SLK3700AMB, which has a stock 120mm exhaust port on the rear, and another extra-deluxe one is the Lite-On FS020, which has two 120's on the rear. Both cases have one 120mm intake position available in front too, and are fairly plump.
Here's the
SLK3700AMB and here are photos of the
FS020, which has "radiator" written all over it.
