I'd ask oneneardykid. He works for Atomic. Ask if Punx are true to size. If they are, go 155. That will ski be like a longer park ski and should last a couple seasons. If your a really good skier or the 164 is shorter maybe bump up to the 164 so you can use it for longer.
Here is onenerdykids profile. Just PM him and he'll get back to you.
Hope this helps.