If 100 MB/s is not fast enough, then the choice should be (SATA) SSD, not necessarily an Enterprise HDD, which do not guarantee minimal data transfer speeds, afaik. Enterprise HDD have 7200 RPM or more rotational speeds, but that is a guarantee only for noise and power consumption.
Backblaze has always followed the policy of buying the cheapest HDDs they can find, their business model is successful enough, and they are open about the failure rates of the HDDs they use:
Hard drive failure rates on an annualized and quarterly basis for 139,867 hard drives by make and manufacturer.
www.backblaze.com
Comparison of all hard drives and SSDs on Amazon, sorted by price per TB
diskprices.com
I have been collecting 10TB WD Elements external hard drives to build a 5 drive NAS. I purchased several in the spring and early summer, some of which got given out with 2 remaining. I purchased 3 more in mid-August. I have finally gotten around to building the NAS. The two older drives are not visible in BIOS. The M/B is a 3rd Gen Intel. Neither can the LSI 9211-8i HBA in IT mode. I have swapped all connections and nothing.
Working model is WD101EMAZ-11G7DA0
Non-Working model is WD100EMAZ-00WJTA0
-S
Bare drives from external enclosure not showing up in the OS has happened to me a few times, what solved it was to delete all existing volumes or partitions on them and format them again new (Quick Format is enough) while in USB mode (or while they are still in the enclosure), and while using the OS you will use them as bare drives in later on. Then you connect them on in SATA mode, and know where you stand.
It is also strongly recommended to keep the SATA to USB interface circuit board that you find in the external enclosure, precisely for these situations, and for that reason to open the plastic enclosure as carefully as possible. There are YouTube "dismantling" videos for every plastic enclosure model. Some of them are boring and not really helpful, but you get to see how the enclosure is build, you realize how to open it and how to not damage the drive inside and the circuit board when you open it (which always require tools and some brute force).