The Giulia series (105) are a great source of enjoyment to many of us and I'm sure there would be a lot of help available to you through our club. Please consider joining if you haven't already and you too will enjoy the fellowship of members with like interests in a wide range of activities.
When sourcing a car look closely at the re-build quality and history (photos of the restoration are always a help) as these models are now 40 years old and will either require restoration or have had such repairs previously carried out to varying standards.
Mechanically they are very easy to attend to and with a little care and attention to detail track times will often be faster than the 'big bangers' that you mention.
They also make good daily drivers, as the power, braking and handling all stack up well against more moden vehicles.
Look to purchase through all the normal channels, there is a couple on e-bay at present and there is a nice Green 2000 GTV advertised on our buy and sell forum. It is is Adelaide though. Our club magazine 'Cross & Serpent' regularly has cars in the 'for sale' section too.
Remember it is alway good to have some one in the know help you with a pre-purchase inspection to save some grief if you are not completely familiar with the type.