The 3 basic layups are still available and whilst these have progressed a huge amount over time, the 3 options are still here (with the improved built weights I now go for the carbon skinned version for the Willows)-
All have the same excellent main spar in the wing and 2.4gig frendly fuz.
1, A fully glass skinned version
2 A carbon D box and glass skinned wings
3, A Carbon skinned option, which will have 93g skinned wings.