I did the upgrade to my Navara with EFS.
made it a completely different vehicle...for the better.
Australian made product and a 100,000K warranty.
I also did the upgrade to my 2009 Collie at 30,000k's due to flattening out of original leaf springs. That's got 170,000k's on it now and suspension is great.
My work shop guys are On Track 4WD at Slacks Creek. Brett is a no bullpooh type of guy and will only sell and fit exactly what you need, not what you want... if you know what I mean. That is, he won't sell you overkill suspension, lift kits etc etc that you'll never use.
I will pm you details.
cheers Phill