WB stato AC doesnt really work in a commercial. The big heater box in the engine bay is the same but the ducting box inside the cab is different. The cable that opens the heater flap works in the oposite direction to the commercial one and it wont work with the commercial controls. Just telling you before you put it all in and find out. You need to get the inside firewall bit from a hj-hz car/commercial. If you sit them side by side they look the same, but they are not.
Forced air uses the center vent in the dash. So as it was optional on HJ most HJ dash facia had the center hole filled in/not cut out. Makes no difference to fitting AC.