Replying to Bindings for me

I need bindings for my Fujatives that I just bought for $165.
I weigh 120-125 lbs, and I'm 5'6".
I want the bindings to last at least 2 seasons.
Since I don't weigh a lot, I don't need those PX 12s that everyone is recommending, right? Maybe a lower model?
Also, are the only things that bindings have to do is to stay attached or detach in the right situation and to not break? Or is there something else that separates the high quality ones from the low quality ones?