Yea... just because it looks cool and happens to come in a 159 is not sufficient reason to buy a board. I mean pretty much EVERY board comes in a 158 or 159... and obviously you shouldn't be picking stuff for looks.
You are know heading into boards that I have no personal experience with. I leave you to you window shopping... personally I think going to a store is worthless for a snowboard (boots and bindings yes). Unless you are expert... there is very little useful information you can get just by ogling/fondling a board. You need to take it out for a spin to really learn how she rides.
Uh..I have a bg 162
If you're 155lbs I'd skip out on the 162 and go 159 or below depending on where/what you ride.