If you can get the stuff listed on 'minor defect' you can get it cleared at the police station - I'm curious about the no air filter - does that mean you have pods instead of a box, or do you have a box with the filter medium removed?
Getting the filter fixed and new tyres is infinately cheaper than having to go thru regency, mainly because you will need to go thru twice by the sounds of it, and removing the turbo and cams is a big job. You'll definately need to remove the boost controller and turbos, you may get away with leaving the cams in. Regency know what to look for, you can't bluff them on EBC and turbo timer (and if you have a turbo timer, just get rid of it, TT's are only useful on track cars).
I'd be fixing those things and visiting sturt police station or another one which can clear it for you. Regency inspection will cost you a lot more.
-D