Hi Northy,
I would recommend 5.8, 5.0 and 4.5. You have a small size which keeps you going if the wind is loosing some power. The 5.0 works great in waves with lighter wind. And the 5.8 can bring fun on flat water or chops with lighter winds. Fur sure you also can sail a 6.0 on the 80, but most common sizes are from 5,7 to 4,5.
All the best,
Chris
www.chrispressler.com