A bit of an update on the scan tools. I've ordered an ELM327 1.4a interface off eBay for a whole $24 which supports the ODB2 protocol that Gen4 VZ/VE uses.
I've also looked into the PCMScan/ScanXL software which appear to be pro/generic versions of scanning software from Palmer Performance Engineering. Holden is on their
list of supported vehicles however I'm not holding my breath for all of Holden's custom PIDs to come through.
I'll start a dedicated thread when I get everything up and running.