Considering a Jacknife, I'm 6 ft, 88kg, intermediate (I guess), 40 yrs and in good shape. Have a 6'2 Quadfish HP which goes great in the smaller stuff. As I'm improving, I'm looking for something leaner for the better waves (autumn/winter). I definitely need a little extra volume - a regular shortboard is not for me.. On the other hand, funboards and "big guy shortboards" are too much foam. We wear thick wetsuits here, and booties and gloves. I'm thinking 6'6, or could I get away with a 6'4? Any advice is appreciated!