China is invested in almost everything. Phytium or Rockchip for ARM (large and small respectively). FeiTeng Galaxy FT-1500 runs openSPARC. ShenWei Sunway series runs Alpha. Suzhou PowerCore runs openPOWER. I can only imagine they have a bunch of work going into RISCV too.
Can either be purchased online by customers outside of those countries?
You used to be able to buy Lemote Yeeloong notebooks, which in addition to having Loongsong processors had completely free software BIOS, making them one of the only RMS approved pieces of hardware. But I'm not seeing those readily available any longer.
I believe you can still get them but its not as easy.