For east coast I would go SFB, the petitor and the opus may feel like overkill at times. But if you perfer a wider ski then you shouldn't have a problem with the first point. The SFB will feel the most comfortable on those occasional park laps, not only because of the smaller waist/dimensions, but I have also heard quite a few people say the SFB feels like a beefed up park ski. In terms of flex the petitor will feel the stiffist, then the Opus, then the SFB. For steeper terrain I would most like to have the Petitor under my feet but for mellower treed runs and messing around on smaller features on shallow slopes the Opus or the SFB would be my pick, depending on the snow conditions as to which I chose.
Hope this helps, as I have never personally experienced east coast pow or had the chance to ride any of these skis it's difficult for me to say definitively which ski would suit you best. Joey