OK, so accepting that this is something akin to camping we can narrow it down a tadge.
Nothing wrong with the camping aspect of course , just as long as folk realise that Bent is not looking for a round the world cruiser and that he is limited by his rather careless aquisition of a wife and four sprogs.
Lake Macquarie btw is Australia's largest coastal salt water lake roughly twice the size of Sydney Harbour and connected to the Tasman Sea by the Swansea channel. A daysail up or down the the coast will see you in Port Stephens or Broken Bay.
... and so to boats ....
Carter 33 ... nice choice but as you realise you will be pushing a barrow uphill to find one at the right price. One in Newcastle under offer at sub $30K. bit of a roughy but otherwise looks OK.
Southern Ocean 32 looks interesting and also looks like she'd be a nice thing to sail. Has the berths but otherwise pretty cramped.
Me, I'd be more inclined to consider the idea of four berths down below and camp in the cockpit. A decent boom tent would supply sufficient cover though admittedly in heavy rain you would be pretty miserable but hey, four sprogs, the missus and you are not exactly going to chirpy in anything 30 odd feet when it is bucketing. Crikey its hard enough keeping two anti social misfits like me and the talkative one happy in a wet 30'er. You know this already, so no real need for me to tell you again what ? However, with six of you on board you will need a decent sized cockpit anyway, why not take advantage of the cockpit seats as bunks ?
ps - Swanson 28 .... maybe a bit slow if you are thinking of doing the odd club race but lots of room and I think they sleep six. Probably a bit of a roughie in your price range.
and this .... i know nothing about them but reputable builder and if the cockpit seats are long enough she would sleep seven.