[Zedn]

You need to comply with the emissions for your state.

Decide if you want to go traditional ford or join the dark side. Try and get your hands on a coyote if you want ford or go an LS3/2/98 etc if you want chev.

Stock standard is the way to go for emissions compliance. You can get modified engines through, but be prepared to drop a stack of money on tuning and failing a few tests. All of these motors put out plenty of power in stock form with a mild tune.

Please talk to all the manufacturers in Aus before going with an OS supplier. The industry is struggling enough as it is. Im sure any of the manufacturers will be able to help you with all parts needed and expert advise just a phone call away.