Helm of the tracker was another one that could be customized but was separate from the
custom plate helm quest
For the quest it consisted of all plate class helms from the velious class armor, the king crowns (tormax and dain) and cowl of mortality. I don't believe white dragon helm was customizable (I even tested it on live didn't work). The custom helm design that would be shown follows the race and sex of the character ie Human male/female characters showed a gold dragon helm, dwarfs males a gold helmet with horns, iksar males with an alien facehugger, etc
This
link shows a few more images of the custom helm for various races