in case you weren’t aware, gpu transcoding requires plex pass.
if you don’t want plex pass, then I would probably stick with AMD.
otherwise, look for an intel 7000 series CPU or newer, with 600 series igpu.
if you have any intention of transcoding 4k/hevc content, be prepared that the cpu requirements are very steep.
more 4k info @ [INFO] Plex, 4k, transcoding, and you - aka the rules of 4k should you go be going that route.