Hopefully I am not too late here.
Get some Womens bindings, size M, or L, try them on. Lexa are good. The straps will fit better. Fuck colors. Get hot pink, none cares.
7.5 boot is tough. Remember the waist is at the center, so the board tapers a lot. good luck, if you are a good rider, that board will rock no matter the size of your foot.