I've met a few guys that have come from Toowoomba to Victoria point to sail so there are people that windsurf from toowoomba. not sure if they use seabreeze.
Ive looked on the map for Manly. the area looks like open water.. You guys get a lot of bounce on a good day. Im going to be there April 7-10. If there weather is ok I can head down for a sail on the Saturday. So speaking of weather wich works best there.