I'm in the same boat as you buddy. 5'9". I was looking at Domains, thought about picking them up. I would probably get a 179 if you're down with over-head sizes.
Ya see that's the thing, When I started skiing 6 years ago I was 11 so the height difference is pretty big. And I've only had two pairs since, the last ones were my first twin tips too.... So I have no clue what I should actually be getting.
179 and mount them near center. I did the same thing as you and bought 165's and outgrew them and I'm only 5' 8". I'll probably never buy below a 174 again.