Acording to the chart someone your height and weight who is a type 2 skier won't be set higher than 5...so I'd go ahead and get the Z10, super lightweight, you won't break it because you're small, and it's brand new so it comes with a factory warranty. I'll give you the links for the sale at getboards.com, on has an 80mm brake and the other has an 85mm brake...just choose the one that fits the waist of your skis best and buy it, super good deal.
80mm brake version:
http://getboards.com/snow/bindings/salomon07/z10_b80.html
85mm brake version:
http://getboards.com/snow/bindings/salomon07/z10_ti_b85.html