Ree,
Wow, That's great life you have gotten on the cell. Many of us have used Discount Salt Store. If you go with an OEM replacement make sure you comply with warranty. Most majors reduce the warranty for new units and I'm not sure what your brand does for replacement parts. In general, 3rd party manufacturers do not reduce warranty for DIY. Just read the fine print to be sure. Even though you got great cell life out of the original cell there are a few that fail from all manufacturers. As you probably have discovered in your shopping a cell replacement is big $$$ so you want to protect the warranty.
I hope this is helpful.
Chris