LF Alpha bindings fit.

Hey guys, this is my first post here. We have to buy a new board and bindings since some punk stole everything out of the boat.
Anyway, I think we have settled on a board and bindings. From what I have read here, it sounds like the size recommendations are a little off. I like the LF Alpha bindings or maybe the Transit. I figured we would need a large but do these things run kinda big? I saw a couple of guys saying that they recommended a Medium for a size 10.5 foot. We will have anywhere from a size 9 up to a 11 riding the board. Do we need a Medium or a Large? Thanks for any advice.
Oh, which of these two should we go with for Beginner/Intermediate: Both LF's, Trip 138 and Fusion 139. All I can see is a difference in rocker. I am leaning toward continuous while my buddy is thinking 3-stage.