This turns out to be remarkably difficult. If I search for NAS drives (on the assumption that they've got TLER), I end up with WD Red, WD Red Pro, Seagate NAS, and Seagate Enterprise NAS as my only options.

I'm considering buying 1 WD Red and 1 Seagate NAS from one distributor, then waiting for a couple of weeks (or using a different distributor) and doing the same again to see if I get a different batch...

Or am I being paranoid?