I'm 6'0, 195 lbs, the local shop guy told...
I'm 6'0, 195 lbs, the local shop guy told me to get the 155 Scallywag.
Is he right? I am concerned about my weight, not the length
Yeah you'll be fine with that board. I'm your weight and my two boards are a 152 and a 156. A 155 will be good for you if you're riding park and cruising the mountain in a less aggressive and more freestlyish way. If you don't ride park then you don't want this board.
Run the 158 if you are concerned for your weight. If you only ride all mountain then run the 158. Good times for sure.