Jabsco ballast puppy replacement impeller?

I used the search but couldn't find the information i was looking for. I've been looking online and found replacement parts for the ballast puppy of 6303-0023 6303-003 and 6303-0001. I need to replace the impeller on the ballast puppy from a 2003 mastercraft x-30. I am looking for the right replacement number and also a good place to buy one from. Online i found two different numbers from the pump 18220-1123 gives replacement number 6303-0023 and 18220-1121 gives replacement number 6303-0003. The title of both is the same pump so i was a little confused by that. Any suggestions would be great. thanks