Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.
Best bang for buck.. L67..
Not sure about over your way, but in Sydney @ commwreck (probably the best commodore wrecker in the state) a complete low KM l67 conversion (engine, loom, trans, tailshaft, ECU etc) can be had for $1800, so for around $2000 (to allow for anything extra you might need) you have a turn key l67 in your car.. Great base for supporting mods, like smaller pulley, cooler etc...