Replying to Nordica OMW Size Help

So i am 5'9" and will be 21 soon and i have skied the same 166's the past 4 years. i want to get the omw's but i am not sure what size i should get, it is offered in a 170 and 177. Im on the east coast and i ski mostly park, unless theres powder than i will be in the trees. The biggest size it comes in is a 177, which makes me feel like it is for taller people. I also dont want the ski to be too short because im not sure if nordicas sizing is shorter than whats marked.(example Line skis usually run a little shorter than marked). Ive searched other threads for advice but i havent came across much. +k for help, thanks!