Replying to Ski length questin again.

hey guys i am 5'8" and i am getting the salomon 2012 cause i live in australia they are out. Now i currently have 2009 suspects that are 171 and i love them. hence me choosing the 2012's. i don't know wheather to get 171's or 179's. i will have no trouble handling the 179 for general skiing but i don't wanna loose the light and easy feel of smaller skis in the park. 175ish would be perfect but it isn't an option. what do you guys think?