My son is going to the states next year,and if he finds a camaro or mustang that he likes he wants to bring it home.  So who is the best person/company to talk to and what are the pitfalls.

This is why he want's to buy over there.
a 2010/2011 $25 to 35 k for the camaro
or a 2011/2012 $15 to 25 k for the stang
Oh you can buy a real chev comaboor for 4000

Here's a few links  -http://www.infrastructure.gov.au/vehicles/imports/
 
I had a mate use these guys for a '67 Mustang.
 http://www.cargoonline.com.au/index.php?utm_source=adwords&utm_medium=ppc&utm_term=ImportAustralia&utm_content=I91&utm_campaign=CarImportAURealLTST
 
Cheers
 
Matt

A guy I work with has just done it with a new camero.. there are companies over east who specialize in it and looked after the whole lot. He bought new, so someone over there collected it and then 'sold' it to him second hand (as the rules are different for new cars). It wasn't cheap by the time he had it imported and converted to RHD.