Chris,
Have seen plenty of Dual Cab Patrols & Cruisers, the "chop"is done by Custom Conversions in Brissy, they also extend the wheelbase - from memory the cost is about $20k but that was a while ago.
And no, I don't have any affiliation to them, just seen some of their work - not sure if you would want to spend the $$$'s & use it as a tractor though!