Definitely go for a wide board. The widths vary, depending on manufacturer and size but with a 12.5 boot you will have too much overhang on a regular board.
As for the bindings, what terrain do you plan on riding? Park or all mountain or high speed bombing? Since you are a beginner you'll probably want a medium-stiff binding that can do a bit of all.
Are you on a budget? And why are you only looking at the 3 brands mentioned above?