you can see the xtra plate that widens the track in my front end rebuild thread
http://www.projectpuma.com/viewtopic.php?f=64&t=11063" onclick="window.open(this.href);return false;
If you were going to fabricate your own, I would go to a proper engineering business as weld quality is essential as fabricated wishbones have been known to fail, which would be an expensive mistake to make.
Simon