There are poly spacers available for the coil springs that would add about an inch. Beyond that, you'll probably have to get coil springs custom made to add height.
Carefull with the air shocks in the back. Check your shock mounting points on a regular basis. Air shocks can beat the crap out of the tin back there.
Carefull with the air shocks in the back. Check your shock mounting points on a regular basis. Air shocks can beat the crap out of the tin back there.