Also depends on what style of riding you may be in to. there are quite a few variables as some have mentioned earlier.
U can usually get away with a slightly shorter board if it is rockered. What is the specs of the board(s)? waist width etc? your size 10 boot should be ok.
If all you wanna do is carve the mountain I would personally be looking towards a longer, cambered board.
Give us some more details about your desired/anticipated riding style, board specs etc