184 at the lowest. I would even consider the 190 length. I'm 5'11 220lbs skiing out in utah and would ride the 190. If you are skiing anywhere in the east or plan on spinning them I would go 184 to get some extra maneuverability and less ski in the tight ass trees.
Line skis measure short. The 184 measures out to 180.5cm according to blister gear review. Sauce:
http://blistergearreview.com/gear-reviews/2012-2013-line-sir-francis-bacon