HDDs/SSDs (and old computers) (Bishop's Stortford CM23)

I'm looking for working hard drives (HDDs) or solid-state drives (SSDs), any size or brand.

They’ll be used for a project I’m doing with my son. I can securely erase all existing data (e.g. ATA Secure Erase / SSD sanitize, or a full overwrite wipe for HDDs). If it helps for peace of mind, I’m happy to start the wipe in front of you (or show the erase screen) when collecting.

I’m also happy to take older desktop PCs or laptops — no need to remove drives; data will be securely erased, usable parts reused, and the rest recycled responsibly.

Many thanks!