As per my pm
Try
http://www.poly4x4.com.au/ in Vic
or
http://www.j-p-r.com/ in QLD
or
http://www.eddywreckers.com/ in SA. I have got parts from these guys before.
A new one from Jeep is $1200 & a custom one with uni's instead of CV's is around $1300
A few tricks I use on eBay & gumtree to find what I'm after is:
Search Grandcherokee (no gap)
Phone the wreakers that show complete cars & ask if they have the part.
I do recall seeing exchange ones when I was looking but I cant find the link anymore