Join the hundreds of thousands of others who have used Cartridge World all over the world. They give a good service and are reasonably cheap. I used them for some time before I went over to CISS on 2 printers without problems.
One thing to possibly be careful of is sometimes they take your cartridge and give you another which has already been filled to save time but if you want to make sure you get your own cartridge back again then you have to wait about 20 minutes. Replacement catridges are normally OK but you can never be sure how often they have been filled before whereas you know with your own one.