as for the microtech im not too sure if there are guys running it here in perth but i know that a fair few do so in the eastern states. its best picking a respectable tuner and then ask him what he does best coz the engine management depend on how well the tuner is able to do it.
other options that wont break the bank are the Power FC and Wolf 3D. wait for the gurus to come on, they'll tell you more