For a Patrol we generally recommend going the 12,000lb if you can afford it. You can get away with a 9,500lb but you're likely going to need to use snatch blocks and double line pulls more often (not to mention it being slower).
As for our distributor in Darwin:
Discount Auto Parts
1 - 11 Stuart Highway
Darwin, 801
NT, Australia
Phone: (08) 89460082