Jen, I think those are the ski my wife own (though I have to double check).
Basically, those are "Einsteiger" (amateur) skis, for prepared slopes (don't expect to go off-piste with them) and good low-med speeds and wide turns. Your basic amateur carver (they will turn on their own).
The tyrolia bindings go with them: the ski has a built-in rail and the binding just slides in, no need to open holes in the ski: A snap to upgrade or to lend them to somebody else. Also, this system adds height to the ski, so you don't need an additional carving plate.
The DIN settings are standard, that is the range most non-pro skies will accept
What size are the skis? you say 159cms and then 150??? the should be between your shoulder (absolute shortest and your nose...This type of sky lacks the rigidity required for longer ones) Besides, for carvers, the shorter the easier, but you sacrifice stability at higher speeds.
If they are in good condition (both underside and edge) and cheap, get them.
Head is great for boots as well
I like the feeling of the head skis, very solid, but I personally use/own Blizzard skis since they are ver light