While this thread is still active I might as well answer some of the questions...
Chrno Crusade was liscensed by ADV during the Japanese run of the series, about episode 13 I believe it was. ADV also picked up the liscensing rights to the manga as well as the anime, as of right now Volume 2 of the manga has been released and I believe Volume 3 is coming out later this month. The series first DVD volume is slated to be released September 28th of this year and possibly coinciding with ADV's plans to show the series on The Anime Network.
The series is 24 episodes in length with Zero being an omake of sorts, expect that to be one of the special features on one of the DVD volumes, probably the first or last volume. The series also ended about a month and a half ago, if memory serves me correctly.
I invite you to this area of Asuki's forums...
http://forums.animesuki.com/forumdisplay.php?f=35
This is a whole category specific for Chrno Crusade discussions.