The JetBoil (which I own) shares a very common stove--canister connection with many other stoves, called a Lindal valve.  Examples of other stoves with this valve include the MSR line, Brunton, SnowPeak, etc.   You should have no trouble finding fuel in almost any store that sells equipment to campers, mountaineers, etc.  For example, Mountain Equipment Co-Op (the Canadian version of REI) sells a full line of Lindal valve canisters.