I think you can ride a snowboard that is around 158-162cm longer or shorter depending on the type of riding you prefer. What's the percentage of free-style and free-ride that you think you'd be doing? All-mountain boards are the best of both worlds in terms of versitility.
You may want to look into reversed camber technology (aka banana, BTX, rocker) versus traditional camber.
You might want to get a wide board because of shoe size
Some great all-mountain boards that are
Rome Slash (free-style all mountain, wide version of the Agent (highly recommended board))
Rome Anthem (all-mountain (same as agent but slightly towards more free-ride))
Atomic Hatchet wide (great all around bang for the buck)
K2 Darkstar wide (all mountain)
K2 Jibpan (free-style all mountain)
Some great rocker boards are
Never Summer Legacy-R (wide version of the SL-R)
Never Summer Revolver (more free-style, wide version of EVO)
Libtech Skate Banana
Libtech Dark Series
LOL, sorry, I might have given you too much to think about now, have fun, and good luck.