about $3,000-$5,000
try www.toymods.org.au
last time I checked there were a few for sale.
If you do plan to get one, be careful as they're old cars (around 20 years) so rust is the biggest killer of them.
The engines you'd want are 4AGE (100kW Japland standard - Aus got 4ACE which is about 85kW), 4AGZE (supercharged), the 20valve (I can't remember the engine code). My mate has a 20V and it sounds mighty sweet, goes pretty hard for an older N/A car.