i have px 14 bindings on my Bibbys and they are more than adequate. I have heard some people claim that they are heavy, but I do not notice. After all I am not going to count grams in gravity sports; this isn't cross country skiing and the weight differrence is neglible for spins. Unless you have twigs for legs (and you are a skier so I'm sure you don't) don't worry about the grams. They are excellent bindings for the money, and I can always count on them.
Don't be concerned about the brakes. Brakes can be bent and any reputable shop will bend them at your request (within reason of course 80mm to 120mm is a no no of course)