Replying to Park Ski Weight/Length

Alright well this past season (since its already over on the east coast) I used a old pair of Scott Punishers which are all mountain skis and they are about 166. I am about 5'6" and they seemed heavy for the park but very capable for smashing through the cruddy mush we had most of the season outside of the park. Looking forward to next season i want to get a pair of pure park skis and i think ive decided i want sime line chronics or the liberty team eiditions. But i was wondering is having lighter skis in the park better which to me it seem like it would be and also would buying a pair that is shorter be better for park. Should i buy my park ski in a length shorter than i would normally buy a ski for all mountain? +k for help Thanks