Manual vs automatic transmission for overloading vehicle?

[Kirk Carle]

I'm finally going to do it and buy a vehicle specifically for overloading in mind. I've been camping for last couple years and love it. But this is nothing adventurous. All camp sites are accessible via paved roads and public rest rooms. I want to get into BLM and turn up the notch a little. I'm going to keep my Volvo XC90, but I want to get something more rugged and purpose built. That said, for overloading, is automatic king or manual transmissions best?