Hi,
I have the 10m B6 and its a great kite.
It's also my biggest kite, since you have a 12, I would suggest the 9m.
I had a 9m B5 and it was an epic kite in the 16-25knot range, the B6 is similar but smoother.
I ride a surfboard primarily, so have a 10/7m B6 combo, with a 8m REO in there just for fun also.
Kitesafe