N6.0 would be hard to beat for open-ocean sailing where you have to launch through surf. I20's are getting cheap, also and the H16 is great at taking abuse, and more manageable if you weigh less than 320. At the lower end of the weight spectrum, my old N5.2 was o.k. once you got out there, but it didn't have enough power to get through the surf if there wasn't big wind.
Have fun,
Michael Coffman
T4.9#32