Which CPUs fit the X14SBI-TF?

It takes Intel Xeon 6 processors on the LGA 4710 socket. Check Supermicro's CPU support list for the exact SKUs validated for this board.

Does it support ECC memory?

Yes. It uses DDR5 DIMM modules and supports ECC, which is what you want for a server. Match the memory type and speed to Supermicro's qualified list.

Can I boot from an NVMe drive?

Not directly. There is no M.2 slot and no U.2 connector, so plan on a SATA boot drive or a PCIe add-in card for NVMe.

Is it good for a home NAS?

It works if you want a Xeon 6 platform with SATA drives and ECC memory. For a small, quiet NAS, a lower-power board with integrated graphics and M.2 is usually simpler.

Does it have onboard graphics and sound?

There is no integrated sound card. Video output depends on the board's BMC and the CPU; confirm the display options in Supermicro's specifications before building.

What case and power supply does it need?

It is a server form factor, so use a Supermicro or compatible rack chassis with the right standoffs and airflow. A standard ATX case may not fit the layout or cooling shroud.