HP ProDesk 405 G8 Mini, or HP EliteDesk 805 G8 Mini.
The ProDesk 405 G8 can take a 35W RYZEN 7 PRO 5750GE. This includes AMD DASH (IPMI), and the Ryzen Pro has a few extra security features from EPYC/Threadripper. I got mine shipped for just $665 including tax, and did the SSD (1TB 980 Pro) and memory (64GB DDR4-3200 CL16) myself for another $300ish.
If you get three of them, you can have a pretty fantastic Spark cluster that consumes only about 100-120W! But yes, they do XCP-NG or Proxmox clusters extremely well.
The EliteDesk 805 G8 can have the 65W Ryzen 7 PRO 5750G, has a copper heatsink (instead of aluminum), has a 2nd NVMe slot, and can be shipped with a 2.5GbE port (you can order the part for the ProDesk 405 G8). Though if you get the 35W 5750GE, you can have an NVIDIA GeForce 1660Ti 6GB installed as well.
Since both use Ryzen PRO processors, they actually support ECC memory as well. I'd argue they may be the best overall 1L form factor systems on the market, especially in terms of performance per watt. The only other thing I'd ever want is 10GbE instead of 2.5GbE -- though in the EliteDesk 805, you COULD get an NVMe to 10GbE Ethernet and install it, just need to make a faceplate to properly mount the port on the back of the chassis.
Did you get it yet? Multiple reports of 1-month-plus shipping delay notifications after the order is placed. I ordered one of these myself and canceled after the delay. Still plan on ordering one albeit with a different config.
Originally I opted for the 5700GE (apparently slightly faster than the 5750GE) thinking I wanted the most power possible in the box. But my new thinking is I really want a 5300GE to pull out and put in an AM4-based silent HTPC for the living room, then upgrade the HP with a separately purchased 5700GE. QuietPC seems the only vendor selling these "GE" 35W models -- but not any 53X0GE parts. In other words buying one of these non-vendor-locked HP minis and ripping them out might be the only way on Earth right now to get one's grubby hands on any 53X0GE.
Also, are you sure there are two M.2 slots on the EliteDesk G8's? I know they are on the G6 but haven't found confirmation the G8's continue the tradition.
The ProDesk 405 G8 can take a 35W RYZEN 7 PRO 5750GE. This includes AMD DASH (IPMI), and the Ryzen Pro has a few extra security features from EPYC/Threadripper. I got mine shipped for just $665 including tax, and did the SSD (1TB 980 Pro) and memory (64GB DDR4-3200 CL16) myself for another $300ish.
If you get three of them, you can have a pretty fantastic Spark cluster that consumes only about 100-120W! But yes, they do XCP-NG or Proxmox clusters extremely well.
The EliteDesk 805 G8 can have the 65W Ryzen 7 PRO 5750G, has a copper heatsink (instead of aluminum), has a 2nd NVMe slot, and can be shipped with a 2.5GbE port (you can order the part for the ProDesk 405 G8). Though if you get the 35W 5750GE, you can have an NVIDIA GeForce 1660Ti 6GB installed as well.
Since both use Ryzen PRO processors, they actually support ECC memory as well. I'd argue they may be the best overall 1L form factor systems on the market, especially in terms of performance per watt. The only other thing I'd ever want is 10GbE instead of 2.5GbE -- though in the EliteDesk 805, you COULD get an NVMe to 10GbE Ethernet and install it, just need to make a faceplate to properly mount the port on the back of the chassis.