Ultrasonic or Futura 131

[rdrsurf]

I am 80 kg and - at least from my view - an experienced surfer. Up to now I am sailing a futura 122 from 2010 with NP hellcat 7,7 and V8 9,0 with a select freerace 44. For 2012 I would like increase my planing capabilities in light winds with 7 - 10 kn with my new H2 9,2. With these winds, my favorite location in souther italy is flat or slightly choppy.
However, gusts from time to time might even go up to 15kn.

Would the ultrasonic still work up to 15-18 kn with the H29,2 and the hellcat 7,7 (the with a 52 fin)

Or would overall the futura 131 or the ultrasonic be the best choice for me?

Maybe the F122 and the F131 might be to closse to each other and the F111 and the F131 might be the best combo? How about that ?

Appreciate your advice on this questions.THX

Regards, rdrsurf