It's actually my first time dealing with a coil suspension setup off road. I have extended the panhard and fitted a drop bracket to compensate for the lift but at the moment the arms are all factory. I am going to do some testing with them first and see how it all works out on the trail.
There are some guys running around on extended land cruiser arms over here but I'm not sure if they increase stability at all. Unfortunately there is not a lot of info about these rear coil suspension setups, may be a little trial and error. And if all else fails chop it out and go back to basics.
Cheers