I have been following this modder on Twitter for a while now, and he seems pretty close to an hdmi mod for the Gamecube, currently in the beta testing stage. If any of you are interested, below is a link to his game site and twitter feeds. We are finally almost free from the cutthroat eBay prices on component cables!
http://www.badassconsoles.com/
https://twitter.com/badassconsoles
http://www.badassconsoles.com/
https://twitter.com/badassconsoles