Alan—the link you posted and the link I posted (for sockets) is the same link—this site also sells parts to assist in making the harness, the male 9004 in particular. I'm making my own harness so I'll have total control over circuit design (the ability to have all eight headlight filaments fired together for instance), wire gauge, length, etc.
"It calls the harness a 9004 or 9007. . . " 9004 bulbs and 9007 bulbs take the same socket. The harness you were looking at can be used with 9004 or 9007 bulbs.