Depends on your computers IO ports.
Go with the fastest possible.
RAID for sure.
Since I’m on different setups (2013 Mac Pro, 2019 Mac Pro, and M1 MBP), I use a variety of Thunderbolt 2/4 drives and USB-3/C single drives.
My most reliable single SSD is the OWC Envoy Pro.
As far as RAID, I have a few OWC ThunderBays and Promise Pegasus RAIDs.
External drives are as good as your host CPU.
The killer setup on my 2019 Mac Pro is the internal RAID card with NVMes.
Again depends on what you have.