Go with the main picture. The WEG book gives the most detailed look at the AATs so I would go with that. If they have white or grey hoses, use those, If they have black T-bits then paint them black. The source you have above is the WotC RPG pic. Unfortunately, WotC isn't known for putting details into their armor and rarely have a solid reference to match (Same lack of detail caused the WotC Nova to be declined as a paint option). The WEG is the one that shows both front and back, so that should be your detail base pic to use.
-iz