Replying to Will a 179 hellbent float?

So I have decided on a hellbent as my new pow ski, I will be skiing whistler and want something that is turny, good for trees and some switch riding.

I have the 179 obsethed, 176 dumont and 181 reno rockers (will probably sell these).

I have been on the k2 website and alot of the guys on their team are riding 189 hellbents and alot of them ski a 179 obsethed with a 189 hellbent. I always thought the 189 was a bit of a brute but if their only skiing the obsethed in a 179 it makes me think perhaps I can get away with the 189 in the hellbent. I will probably be centre mounting these which will make a difference.

My question is should I go 179 or 189 I am 5 11 and 145lbs (not a big guy).