Thanks to everyone for their replies.
To answer previous posters:
We have considered the UK, but have recently heard lots of stories of people moving back and then returning to Australia. Australia has given us so much as a family, so we want to give it our best shot. If the likes of Brisbane and Melbourne (or Tassie) don't meet our expectations, we will consider the UK.
We have now lived in 8 suburbs in Perth, in search mainly of a community feel, and to try and feel a bit more settled, with no luck. We have made a conscious effort to live in suburbs that are not full of Brits, but to be honest, we find the West Aussies friendly to a point, but they don't really let you in unless there is somethng in it for them. If I had a dollar for the amount of times we have heard the saying "must invite you round for a barbie", which never happens. We are very sociable and have invited neighbours and other West Assies around for drnks etc but these invites are not reciprocated. You begin to think it is you after a while but I have heard similar stories from others. I travel to the east coast a bit through work and definitely notice the east coast aussies to be a lot friendliey to.
Thanks to the recommendations on Sydney. I have found Sydney to be a bit brash and plastic at times (although I admit I have not lived there).
A lot of people who bag Perth go on about the heat, the flies, the isolation, the high cost of liviing, but we were aware of most of these through research before we came, so can't complain about these things. The sense of community is something that sadly lacks for us, as too many people retreat behind their garage doors at night, not to be seen until the door goes up the next day. Also, not sure if it is just us or not, but we hardly ever see kids playing in the street here, or many people in the street, which has been the same in the 12 years we have been here - we find this very weird.
e Mornington Peninsula an hour south of Melbourne is lovely and is much favored by Brits.