As Floyd said, 34GT-T, and yeah, there's plenty of places that do the work on them; as for oil changes, it's fairly similar to any car: can either do it at home or mechanic. There's plenty of performance workshops around who can do larger work if need be; there are a few that come heavily recommended by many users on this forum such as Unigroup, though I think Yavuz has a bit of a wait time because he's popular (could be wrong though about the wait).
In regards to meetups: there's always something happening. If you've got a car already and are able to make it down the coast, there's a meetup this weekend, or failing that, there's a fair few events coming up.
Whereabouts in Sydney are you?