Replying to All mtn/ Park Ski length confusion

I currently ride 171 Line invaders that i use specificly for park, but im looking for a second ski to take all over the mountain, to include powder, I am 5'10- 5'11, wear 26.5 boots, and my lines come up to my eye level, and weigh 140lbs, whats the ideal allmountain length (non rockered skis), is it the same or a little longer, for instance would 182 surface watch lifes be alright,(its about a cm taller than me), if i still want to take the all mountains in the park sometimes?