I have a WD Sharespace 4TB unit and it came installed with 2x 1TB WD10EAVS-00D7B0 drives. I want to add two more to the unit but I cannot find them on the WD Store or any local store. I contacted WD Support for an alternative and they told me use their authorized online reseller but they didn’t furnish me any website details. Therefore, I wanted to know on where I can purchase the above drive model (online preferably) or suggest alternatives? Any help would be greatly appreciated.