All of these would be excellent:
http://pcpartpicker.com/parts/compare/corsair-power-supply-cp9020072,seasonic-power-supply-ss660xp2,seasonic-power-supply-ss750xp2s,seasonic-power-supply-ss760xp2/
http://pcpartpicker.com/parts/compare/corsair-power-supply-ax760,evga-power-supply-220p20650x1,evga-power-supply-220p20750x1/
Of course, there are some very good bronze and gold efficiency models too.