I bought a few different seal kits from Edelmann, Gates, and Oreilly house brand (MasterPro). I'm pretty sure they're all the same kit in a different box. They all had almost the same part number and the package inside the box looked the same. It took me a few tries, but I finally found one that all the seals were correct. I think the part number was 8776, but I can't swear to that. Assuming we are talking about your LBZ, that should be the one you need if I'm remembering correctly. Like James said, getting the balls inside is the hardest part. Once you get 2 or 3 going, it isn't too difficult, but sometimes it is a pain to get them feeding in there properly.
edit: the Oreilly part number is 28401430 if you want to find one local.