Sff-8644 Breakout to sas-12?

Howdy guys. I’m putting together a nas an am running across new things that I’m not familiar with. I have a bunch (8) of sas-12 hard drives and I’d like to connect them all to a motherboard via an hba. I’m just not sure what the best way to do that would be. I’d love to future-proof a little bit by getting one of the newer tri-mode U.3 HBAs, but they are using sff-8644 connectors and I’m not sure how to break them out into full size sas-12 connections. I imagine that most servers/drive sleds use backplanes, but I haven’t built a homelab yet so I’m not to the point where I have a drive sled or a server rack. I’d like to use my old eatx case, but that would require breaking the sff-8644 out into 8 sas-12 connections, and I’m not sure how to do that. Do you guys have any advice?

There are just plain cases out there, but sleds plug into PCBs that often (but not always) have an integrated expander of some kind, and sometimes (less often) it’s just a bunch of individual connectors that you’d then need to connect to an expander of your own.

like this one: Explaining the IBM SAS-2 expander and how to do 24xHDD setup with only 2-port SAS controller - YouTube