I just got the Argon chip a week ago on my new Wii. None of the others were compatible, but it's a great chip. No problems whatsoever, plays every game (a few NTSC one's need FreeLoader, but that's to be expected) and all homebrew stuff is working etc.
It's also a fully updateable chip - the guy who installs it will leave a wire just tucked in to one of the air flow vents or something allowing it to be updated without ever opening the Wii again.
Do it
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