> who should I be buying external HDDs from

Trick question. The answer is "don't". I can't find a direct citation for external HDDs being the lowest parts-bin of drives manufactured, but the pricing tells the story enough for me.

My data is valuable enough to me that I usually spend ~twice as much on a high-end drive and put it in my own enclosure. I usually go for IronWolf drives, and I'm a big fan of ICY BOX enclosures: https://icybox.de/en/product.php?id=297