Best SSD external drive for Mac M1 Studio?

I use WD Black SN850 and Kingston KC3000 drives in Orico 40Gbps NVMe thunderbolt cases. I get 2.6gbps. It makes USB SATA hard drives feel like floppy disks:)

Bus powered drives are widely variable in their ability to survive the built-in drop in Bus power when the Mac sleeps.

For best results, use a powered hub or a self-powered drive.

I use the 3 bay NVMe Sonnet Echo. I bought the Pale cards from OWC. I use Western Digital NVMe. It's fast, reliable and sleep with the Ultra. Cost is about $600 but worth it to me. write speed for the WD 2 T about 900 meg/sec and read about 2400 meg/sec The one terabyte WD write would be about 1700 meg/sec

If your issue is not disconnecting after sleeping (known issue) then not sure why they would disconnect. I do not have that issue but I now only use SSD/NVME drives which I suppose could make a difference. Be sure you have good cables as the latest Apple OS is very finicky on robust connections. I went through several cables before I fixed my key pad from disconnecting.

I just bought a Mac Studio & the 2 bay NVME Sonnet Echo. For some reason the Studio isn't allowing for a RAID configuration for the Echo. I really need the read and write speed. Please if anyone can help or steer me to links I'd appreciate it.

Don't ask help for a problem in a post created for a different problem. Instead create a new post.