Hey ,
Will be there from the 1st myself , been going there for 6 years now ,go twice every year , if your staying a decent time , allso get to to Pha Rang , flat water and waves on the outside reef , few hours away from muine.
End of their season so crowds will be slightly better
The trip from Ho Chi Min is only about 4/5 hrs ,road has improved
Take the 7/9 its all you will need , early kite as the wind comes on with the 9 but from 2pm on wards normally the 7 will do most days , they have had a very windy season with bigger waves in the bay than normal .enjoy
Check windfinder forecast is good