Two devices I use - both running Debian, and both being open-source hardware to some degree or other:
PC Engines APU2, AMD x86_64, 4-core, 4GiB, 3x Gigabit Ethernet, 3 x mini PCIe, SIM slot, USB 3, Serial, SATA ports. Mine has dual band WiFi in one mPCIe, SSD in another.
Turris Mox, Marvel aarch64. This can expand via plug and go via a range of extension modules. I've got one with 25 Gigabit (3 x 8-port modules) Ethernet, 1 x SFP, 5 x USB3, Wifi, Serial.
PC Engines APU2, AMD x86_64, 4-core, 4GiB, 3x Gigabit Ethernet, 3 x mini PCIe, SIM slot, USB 3, Serial, SATA ports. Mine has dual band WiFi in one mPCIe, SSD in another.
Turris Mox, Marvel aarch64. This can expand via plug and go via a range of extension modules. I've got one with 25 Gigabit (3 x 8-port modules) Ethernet, 1 x SFP, 5 x USB3, Wifi, Serial.