Well, one size up is 156, which is about perfect for what you looking to do. I reckon it boils down to how much powder you plan to ride - in pow every cm counts!
Note: All of the above (including my previous post) assumes you are looking at the CTX/Clash Rocker version of the Superpark. If it is the traditional camber option then you should almost definitely go bigger.
Forgot to mension: I'm indeed looking at the CTX hybrid vesion.
You may be right about the rager size, but for someone who's used to riding a 152 board and still is a noob in the park, the diea of riding a 156 deck is kinda terriffying:s
My pow dilemma: I wouldn't ride anything else if I could, but the sad truth is that I hardy ever get the chance to ride any pow at all:s
I may just have had bad luck the last couple of seasons, the mountains I been to are normally overlown with powder, but I'm still not sure it's a good idea to blow my heard earned money on a slighlty clumsy and park-unfriendly board:s