Thanks for the feedback guys. Roger, I was kinda leaning toward the path you recommended with the iSonic. I'm considering the 155 as I intend to use sails in the 9 - 11 m range and the width and extra flotation of the 155 seems to be a good call. There is a local semi-formal group of sailors that do monthly formula races. I don't always participate, but, want to have the option to if time permits. It sounds like I wouldn't be at too great a disadvantage against full on formula boards and could maybe get an edge in the turns.
I definitely appreciate any additional thoughts.....it ain't a small investment.