Fractal Design Define C is compact and reasonably priced (to me)
Fractal Design Define R6
Phanteks Enthoo Evolv
I'm assuming that "small ATX" means compact ATX and not mATX....if you meant mATX, then the Fractal Design Define Mini C still supports two 280mm rads.
Main: i5-3570K, ASRock Z77 Pro4-M, MSI RX480 8G, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
HTPC: A8-5600K, MSI FM2-A75IA-E53, 4TB Seagate SSHD, 8GB 1866MHz G.Skill, Crosley D-25 Case Mod