CPU/GPU advice for streaming to 4K

I'm looking to set up a Batocera multi-cade game, and use a 55" 4K TV as my monitor. SNES/Genesis will probably be the heaviest emulators I run for this machine. I know the processing power required is pretty light, but what should be my desired GPU specs to properly display the games to a 55" 4K tv via HDMI okay?I've got my eye on a GMKTec M5 Plus with the Radeon 7000 GPU.