For those curious as to what boards I'm considering, I've looked at a 162W GNU's Rider's Choice for all mountain riding, and possibly a 169 Burton Barracuda for strictly powder. (Both are a ~5 flex)
the burton barracuda rides fairly big for its size. 169 will be a lot of board to what ur used to. imo u wont need the whole 169cm to float on top of the snow and it will be hard work maneuvering through the trees.
also, only get a wide if u actually need it (sz 12US+).. im a size 12 and still try to avoid riding wides, i find them much harder to turn and throw around compared to my mid wides. a wide board wont necessarily make it more stable and if u dont have a big foot it will just mean more work to go from edge to edge.