Air shocks are not lift kits. I know too many people with hotrods that put on air shocks just so they can fit a little bigger tire in the back, then they wonder why the car now has LESS traction with the bigger tires and it rides like crap. The suspension is there for a reason, air shocks pumped up enough to lift the vehicle keep the suspension from doing it's job properly. If you do it, make sure those shockmounts are bulletproof.
As a side note, air shocks on the front sounds like a big NO-NO. It seems like they could disrupt the balance of the vehicle and cause a loss of control bad enough to put you in the ditch if they decided to not hold air anymore or a mount popped off while you were flying around a turn.