If you are stuck on the Coda I would go with the 156. Westmark is a sweet all mountain stick from Arbor too!! Then you could even step down to the 153 for some good playful all mountain and park riding but still be good for the trees and off piste.
Same weight as you. I had the same delimma a couple years ago and went down to 155. I ended up with minor regret, wishing I had the 157. With the continuous rocker and the decidedly all mountain flex/feel I think that board wants you to stay on the longer side of your sizing spectrum.
I ended up selling mine after realizing I need camber somewhere in my board. But I loved the pop and float of the coda. I'd bet the 158 would be plenty nimble in trees and better float.