How do I install Granite (http://tanbrown.org) on an insulated open stud wall?

I want to install a slab of Granite (http://tanbrown.org) on an open stud wall (insulated) and (http://maplered.com) mount an electric heater over it. Do I need to install backer board and (http://maplered.com) thin set, or can I just bolt the slab to the stud wall? JoeB