You will never get a ride as nice as conventional shocks with an air shock. Yes, take them out and replace with a good Monroe unit. Usually the more expensive the shock in the Monroe line, the stiffer the dampening. In other words, if you want a soft ride go with the less expensive Monroe shock.
Do check and make sure nothing is hitting though, but if you just raised the car 1 1/2" that shouldn't be a problem.