I hope the topic spoke for itself? Rather than a third party integration, the live chat could offer related items in the help desk topics to the customer with one click. Predefined questions and auto answers (via search) if the helpdesk is busy or operators are offline.
 
(Low priority compared to FCKeditor Joomla and Auto Ship).
 
P.S. ViArt integrates easily in Joomla with the wrapper function using the percent of display (i.e., 75% or more) in most templates.