Id like to start doing a little freestyle but mainly free mountain. The board I am looking at right now is a 159 or a 164 2009 burton canyon Is the 159 too small and is the 164 too big? Any suggestions on the sizing appreciated
A 162 would be perfect for you, but thats not an option. The 159 will be good for you to do a bit of freestyle. If you only did freestyle I would say not to go any bigger. I have a mate the same size as you who rocks a 155 freestlye board. The main issue will just be that float in pow will be compromised a bit.
The 164 would be just right for you if you only did freeriding. It will compromise a bit on park riding, it will be slower to spin and be a bit stiff for rails and boxes (will tend to want to pop you off).