Getting all exited about a couple of centimeters
AT your weight since you are clearly not looking to freestyle much why not go with the 159
You could also go 156~157 without any issues IMO.
I am 170lbs 6ft and mostly ride a 157 proto, I find it spot on for all mountain freestyle personally. Carves pretty well too. I also have a 161 stiffer cambered deck which is clearly better for freeride and is perfectly OK for 3s and mellow freestyle.
I rode a 165 before that and I personally have found that the newer boards do allow better stability and float at a shorter length. Having said that if I want to bomb I like the 161, the 157 is good at speedy carving, but I wouldn't take it up to the same speeds as I feel comfortable with on the longer cambered deck.
All in all everyone has their preferences and opinions. Lonerider clearly likes longer stiffer decks for riding the mountain, but thats not to say you can't carve or ride steeps at speed on slightly shorter decks.
I personally wouldn't be riding all mountain on a 154, I wouldn't ride anything bellow 157 for what i like to do. Each to their own