I think this project is basically done, so in case anyone else is considering a similar concept:
We are moving house and office over the next year plus and need a single server for both purposes. Our design requirement was for a reasonably quiet, portable and somewhat rugged rack-mount server that could be used in our office during the day and play DVR shows at night. Although not a requirement, we wanted Intel Quick Sync Video for hardware encoding work videos.
The universe of Xeon processors with QSV and driver support in TrueNAS-SCALE-22.12.2 is small and is basically the Intel Xeon E-2300 Series with the LGA-1200 socket. We chose the E-2388G with 8 cores / 16 threads @ 3.20GHz, which seemed the most capable.
Our preference is for Supermicro motherboards and the X12-STH-F was the logical choice (actually the only choice, since the other LGA-1200 boards were for specialized purposes). The microATX form factor was a bonus.
We were looking at 2U SSD chassis and had lots of choices. SAS3 was the only requirement. Current generation chassis supporting NVMe were quite expensive and we found previous generation coming off lease at a reasonable discount. We chose the SuperMicro SuperChassis 216BE1C-R920LPB.
We used the standard Supermicro cards for HBA & 10GBe.
Assembly was straightforward, but we found the CPU temperature hovered at 80C. Although we were advised that temperature was "normal" for QSV-enabled CPUs, it did make the fans very loud. Not finding an air cooler with dramatically better performance than the Arctic Freezer 11 LP we originally selected, we decided to try a custom liquid cooling solution for 2U servers. Though expensive, it wound up working very well and easily keeps the CPU at 60C in a 37C room.
We heard the advice about not using cheap SSDs, but with local and offsite backups, decided to take some risk in exchange for convenience and structured the main pool as 3 VDEVs of RAIDZ2 with Samsung 870 QVO 8TiB drives. We added a metadata & < 64K block VDEV with 3-way mirrored and striped Samsung 850 Pro 2TiB SSDs. The rationale being to limit writes to the cheap drives.
iX Apps are on their own 2-way mirrored Samsung 980 Pro 2TiB NVMe. There's also an Intel Octane M.2 that we haven't decided what to do with yet. It's working as a transcoding scratch directory for now.
Usable Capacity is 124 TiB.
The server fits in a large suitcase and weighs just under fifty pounds including the drives.
Pricing, for what it's worth. The CPU was more expensive than I had expected, and ECC RAM was harder to find than I expected.
SSD pricing was very volatile. I wound up buying over several days from eight vendors.