afterbangs would be the best choice i think
mine, i dont feel are heavier than other park skis i have used
You basically described what afterbangs and invaders were made for. Either of those would be great choices
Invaders FTW! Try to find some 171s or 178s! Preferably 08 and newer because of the carbon ollie bands. Gives you some more pop.
Only reason why I say Invaders over A-bangs its because they are lighter and they don't have the extruded bases (which wil cause the ski to be a bit slower) so they'll perform better all mountain rather then just solely in the park.
Other then that they are both symmetrical flex, symmetrical dimensions, and both have butter zones making them some of the most playful rail killers out there.