There are six Famed and rare items that have a freezing skill, all of them Cursed. The easiest one to get is the Bitter End, which is obtained through the Raven's Cove story quest. The other five drop from Raven's Cove ghosts (excluding Foulberto Smasho) and Davy Jones' crew on Tormenta once you unlock cursed blades, also through the Raven's Cove quest.
There are also two legendary weapons with freezing skills. They are far more difficult to obtain. For them, see: Where can I find Legendary Weapons