Do you feel like the 161 is limiting you in any way? If not, stick with what you have.
Well, I am about your size, but I will agree to an extent. If you looking to launch down wide open runs, I would suggest maybe a longer board, but note it will be harder to make tight turns. If you are eventually looking to get into tree runs and such, a shorter but stiffer board may help make tight cuts and maintain stability.