Pure pow slayer? I'd go Premeir F1 165 if not even 168. I'm 3" shorter and about 25-30# lighter than you (when I'm in shape, not at the moment unfortunately) and I'd probably go 163 and wouldn't pass up a decent deal on a 165.
If you were looking for this as an all-mountain board, I'd say 163, but for pure pow slaying? Go big.
I have a 165 Arbor Element that I ride in pow and it takes a little more effort to throw it around in the trees, but the extra float is worth it when it's deep.