If shocks are bad good bet your springs are shot. If you go OME and spring you do not have to do a full lift but will still lift it some as for sure your old spings have saged. The only dif changing springs is changing rear springs as the fronts have to be pulled to change the shocks anyway.
Oh and the ride will be a LOT better. Also if you change shocks you still have to do a frontend alginment.