Firmware version. I’m having trouble trying to recover information from my Seagate Momentus

Question

I’m having trouble trying to recover information from my Seagate Momentus ST910021AS. It got broken, perhaps the servomechanism reader, and the company that is doing the recovery told us that is necessary to get another HD exactly the same, even with the identical firmware version (8.04). Is it completely necessary? Can I just find the broken component? Where can I find the Hard disk (even used or refurbish)?