Smaller for jib, bigger for park, bigger still for all mountain, and biggest in pow. Though with rocker they are all kinda blending.
I weigh 145. I ride a 150 for straight jib. 152 for park. and about a 156 for all mountain/pow.
at 180 I usually recommend around 154 for jib, 156 for park, 158ish for all mountain and 160 for pow.
Now my jib board of choice at the moment is a Signal Park. I owned the SubZero in a 152. When you get a jib board that soft and its rocker, size up unless you're only hitting street. It will give you some stability to get around the mountain and to set up for features.
I suggest the 155 Draft over the 153.5 so that it isn't completely useless outside the park. And actually in that size with its softness, you can even get away with some powder on it. I rode my 150 on some 2-3 foot days, its soft so I could bend the tail to get float. Not ideal, but doable.