Jake,
I'm pretty sure anything from 18ft to 20 ft. that comes with a "stock" spinnaker is OK to race from the prelim information I have been told. I think there is some discussion going on regarding the spinnaker on the 6.0 as to wheteher the New England configuration is the new standard to be used or something being proposed by the factory??? I'm sure they will find a way to include the 6.0...check with Rick Bliss for the latest. I know the I-20 is good to go though.
All the best,
Jim Stone