108s are more practical for everyday stuff and can still handle pow, they are a little lighter and more nimble so you might appreciate them if you are more used to a park style ski.
116 is great for pow days and are still decently manageable on everything else.
I am 5'11" 140 lbs and ski a 181 Jeffrey 114 pretty much every day, can handle firmer stuff pretty well, bomb through chop, and float well in powder. I think if I ever directly replace them I would go with the 108 in a 186 though.
Don't pigeonhole pow skis as "truer powder skis" some people like to ski pow skis on everything and they can excel in everything depending on the skier's style. If you are the type of skier who stays glued to the ground when it's firmer and likes a little extra weight, but then like to be really playful on pow days go with the 116. If you have a more playful style more of the time and are willing to sacrifice a small amount of pow and chop performance, go with the 108.