NAS Motherboard N100 with 6 Bay SATA3.0, Mini ITX Mainboard with 4 Port i226 2.5GbE LAN, Soft Router Board DDR5 with Dual M.2 NVMe, PCle3.0 x4

You don't need an HBA card if the motherboard supports the number of drives you want. In this case, 4 or more. Prices for the N100's have jumped up it seems. I'll assume you're in the US. If it were me, I'd probably get this:https://a.co/d/0aRNdw82 It will need a fan attached to the CPU. It's DDR4 so you'll save coin there. It's not fully featured, though, and necessitates particular RAM (google this stuff if you go this route). For double the MoBo price, you can get this:https://a.co/d/06H538Kr I think it was made by CWWK, which made the N5105 board I have, and the new N300 board as well. They make great stuff. It requires DDR5, so that'll hurt right now. Note that the SATA ports may block longer PCIe devices so it may require a riser/extension and a case that supports that. I love my Jonsbro N2 case but I'd get one of their lager ones if I did it again - or just put it in a rackmount case since that's the way people tend to go after a while. Otherwise, I'd highly recommend taking the leap to the latest gen. This board is likely made by Topton and as more features than any <20W server could be expected to have:https://a.co/d/0dpXXVCz 2x2.5GbE and a 10GbE port on 2 separate NICs. It's DDR5, so that'll hurt. Mind the SFF cable for 4x SATA drives each (8x total). One thing that's tricky with any of these N### based systems is the lack of PCIe lanes. This makes it difficult to have enough storage to configure redundant boot and redundant zfs cache drives. I haven't executed a solution yet, but I think my approach is going to be to use the onboard 2xM.2 as mirrored ZFS cache drives, and then use either ...(a) 2x USB to SATA adapters or, (b) a USB to SATA RAID adapter ... to boot from a mirrored pool of low power SATA drives (preferably M.2 SATA drives). ZFS is still worth it even if you don't set up the ZFS cache.