I'm going to be siding my house this fall with Hardie plank & to save my arm, shoulder & back I'm looking for some knowledgeable info regarding air nailer's. Someone told me to get adjustable pressure framer nail gun so I don't go below the cement board surface. That doesn't tell me much since there are so many out there with different angles, size of nails, length of nails, etc. Any help to lead me in the right direction would be appreciated.