ok... so you can pizza stop. Just think of it as you are pizzaing with one foot and the other you are just letting go along for the ride.
What you want to do is start turning in pizza, when you get your skis perpendicular to the fall line, straighten one out. keep doing this until you get comfortable. Once you have that down you will want to start working on the pressure of your skis. When you are going into a pizza turn, say you are turning left, try taking the weight off your left turn. Then to go right, take the weight off your right foot.. this will gradually bring your feet parallel. A skate stop is just a really fast turn with a skid similar to kicking your foot out to stop on a snowboard.