For the sort of $$$ he'd be looking to spend he could probably even afford to send it up to APC and have one of their "Banshee" motor packages installed and tuned.
He's in Sydney so without a doubt my pick will be Micks Motorsports. He's done several late model EVO's and knows how to build the engines strong to get the most out of them.
Afterall, he tunes and works on Aaron's white EVO 9 monster with over 1000hp atw.
Mick loves his job. He builds, he tests, he races. Lots of experience under his belt too.
Before your mate embarks on seeing anybody, get him to talk to Ben from Benchmark https://www.facebook.com/BeNchmarkEvolutionSolutions
Ben's been around for years and a lot of the Evo owners in the Hunter Region trust him.
I've known him for years and he's a top guy with plenty of knowledge who can help steer your mate in the right direction.