i am 5'8" and I got 183's. Length depends on what type of riding you are doing. If you want last years 176 gotamas, go to www.untracked.com.
They should still have the 176 in stock. I ordered the last pair of 183's. This store bought all the 06 gotamas from volkl, so in less a local shop has some kicking around (vary unlikely in the west) then this is pretty much the best and probably only place to get new last years gotamas. I paid the same for last years as this years, so you really aren't saving any money with buying last years.