Sorry mate, I'm in Brisbane
In all seriousness, I've worked with a lot of personal trainers and I would recomend... one of them. He's also in brisbane though.
Since you read this website, you should be able to work out quite quickly if someone is okay or not. Just ask them about deadlifts, rotator work, exercise balance and then lower back rehabilitation.
If they don't know their shit, you should work it out pretty quickly after that list.
Good luck, but yeah... I know a guy who just got his cert 4 in fitness. He's never trained anyone in his life but he charges $55 for 30mins.
Frickin' ridiculous. He's never helped anyone before but he's charging like a pro. Some of the buttmonkeys I've met in the industry, it just makes you shake your head.