Any of the local fish stores sell them, Aquatic Tech, Tropical Aquarium, Salty Critter etc... You can also get them online at almost any shop. Marine depot, fosters and smith, phishy business, eden's gate etc...
There is also a local reefer and C-SEA member that makes them out of ceramic so they do not need to be cured at all and are ready to use. PM Ron (RC name= newsalt1) and ask him about a price. Good stuff!