MANO540: a Mini ITX board with full height PCIe x16 slot
Thin Mini-ITX networking board features six 2.5GbE ports, Celeron J6412 Elkhart Lake SoC - CNX Software
ASRock > B550M-ITX/ac
GIGABYTE H610I DDR4 Intel H610 LGA 1700 Mini-ITX Motherboard with DDR4, Single M.2, PCIe 4.0, USB 3.2 Gen1, Intel GbE LAN Chip - Newegg.com
GIGABYTE H610I DDR4 (H610/ Intel LGA 1700/ Mini-ITX/ DDR4/ Single M.2/ PCIe 4.0/ USB 3.2 Gen1/ Intel GbE LAN Chip/ Motherboard) - PC Maestro
ASRock > Z690M-ITX/ax
Amazon.com: GIGABYTE H610I DDR4 (H610/ Intel LGA 1700/ Mini-ITX/ DDR4/ Single M.2/ PCIe 4.0/ USB 3.2 Gen1/ Intel GbE LAN Chip/ Motherboard) : Electronics
Asrock Fatal1ty Gaming Intel Z370 Mini ITX DDR4-SDRAM Motherboard
Amazon.com: GIGABYTE H610I DDR4 (H610/ Intel LGA 1700/ Mini-ITX/ DDR4/ Single M.2/ PCIe 4.0/ USB 3.2 Gen1/ Intel GbE LAN Chip/ Motherboard) : Electronics
Amazon.com: GIGABYTE Z590I Vision D (LGA 1200/ Intel/ Z590/ Mini-ITX/Dual M. 2/ PCIe 4.0/ Front USB Type-C/Intel WiFi 6/2.5GbE LAN/Motherboard) : Electronics
Mini Pcie To 2 Pci Slots Adapter For Mini Itx Motherboard Mini Pci Express To Pci Riser Card For Sound, Network, Graphics Card - Add On Cards & Controller Panels - AliExpress
MSI H510I PRO WiFi ProSeries Motherboard (Mini-ITX, 11th/10th Gen Intel Core, LGA 1200 Socket, DDR4, PCIe 4, M.2 Slot, USB 3.2 Gen 2, 2.5G LAN, HDMI/DP, WiFi 6E)
Jetway MI92-10 10th Gen Comet Lake Mini ITX, Dual LAN, Triple Display – MITXPC
Mini-ITX Seaberry adds 11 PCIe slots to a Raspberry Pi | Jeff Geerling
ASUS ROG Strix B550-I Gaming AM4 Mini ITX Motherboard, PCI-E 4.0 – MITXPC