IMHO
If you want to sail every day head to Geraldton, keep your eye on the forecast and head to Gnaraloo if it's on.
Perth -> Gero 4.5 hours
Gero -> Gnaraloo 8 hours
If you want potentially epic conditions, but less consistent wind then head to Margaret river and cross your fingers.
Perth -> Margarets 3 hours
Or go to Esperance for some of the most beautiful beaches around
Perth -> Esperance 8 hours
Oh, and remember Gnaraloo and Maragarets have the potential of destroying all your gear in one wipe out