Tough call. Based on weight I would say 157, but with your foot size you could maybe size up to 160. Personally, I would say go 157. I am almost your identical stats (8.5 boot size being the only difference) and I have found that sizing up freeride boards, especially those as aggressive as the alch, can be a bad time. Like completely ruin your experience on the board. That board has such a prime shape for ripping cord and also getting deep that I think 157 is the way to go unless you are absolutely snorkeling AK lines. There's plenty of nose and setback that will make it stellar in snow at 157, yet remain nimble on hard stuff.