I've recently put a kit in mine. Kit obtained from GE Xenon in Melbourne and cost $600. I bought the kit at least a year ago with the intention of installing in work Prado, but they have sat in the shed ever since, so decided to put them in the Disco.
Still playing with the adjustment, as they tend to be pretty bright to oncoming traffic on low beam. But they're definitely a huge improvement in light output. Was previously running 100W/90W halogen globes to try and get some light on low beam - the Xenon conversions are way better than that.
The only issue that I've noticed is that there does not seem to be a lot of difference in light output between low and high beams - just a slight elevation of the beam on high beam. This doesn't really worry me as I'm also running Predators with high beam - hence the need to improve the low beam. But if you were running the Xenon headlights only without any additional lights on high beam, it might be an issue.
Cheers ............. BM