Ski Length - Nordica Soul Rider

Now I know I'm going to get a lot of hate for making a ski length thread but I just can't really decide on my own. I'm trying to decide on Nordica Soul Riders (97 waist) between sizes 169 and 177. I'm currently 5ft 7in around 155 pounds and I'm an advanced skier. I ski in the East Coast and I plan to ski this ski 75% all mountain and 25% park. The all mountain portion will be mainly spent in glades(trees) and skiing light powder(6-12in) but will be still used on piste every now and then and in the park it will be mainly used for jumps. Now I know this ski has a decent amount of rocker in the tip and tail (also twin tip) so it will ski short and I'll probably mount the bindings either true center or -3 so it will feel even shorter but since I'm a former slalom racer i've gotten use to super short skis so it just feels weird buying a 177 length ski but i'm always willing to try something new. Currently my on piste ski is 163 and my all mountain(which is getting replaced) is only a 170 but i'm willing to go with the 177 if that is the best length for me. Any suggestions on which size I should get?