Thinking about upgrading my FType 158 Wood. Largest sail size will be 10m race sail. My weight is 77kg. This is my largest kit so would need to keep the same TOW and plane in 8 knts. Am I correct in looking at the ISonic 150 or do you think I can get away with smaller? Next board down is IS 122. Not racing. Just enjoy high performance gear and going fast on a reach.