SammyDubzwhat's with people putting emojis in thread titles...?
Couldn't deal with that, they had to go.
In answer to the OP the 178 chronic is a physically shorter and lighter ski than the 176 Alpha X, but they do ski slightly longer due to the full sidecut. If you felt that Chronics were too heavy/awkward, I'd go for the 170 Alphas. That said I'm your exact height/weight and i rode the 176 Alpha X (and 178 Chrons for that matter).
there's a certain point where it neither looks good nor functions properly...that's when you know you look steezy - no_steeze