Pete,
Some options:
a) run HQ stud pattern all around. You will need to have the rear VN Commodore rotors offset drilled for oversized wheel studs (do a search on here, or contact Blacky, the resident offset drill/oversize stud guru

). You can then use Chev or HQ wheels front and rear. Lots of offsets available in Chev/HQ wheels that should clear the front suspension. Trim the diff width to suit the wheels you find.
b) run Commodore stud pattern all around. You will need to do the offset drill trick on the front rotors. You will also need to run 26P offset wheels on the front to clear the suspension. Commodore mags and steel wheels are relatively cheap and common (more so than Chev/HQ). Again, trim the diff width to suit the wheels you find. You may need to have a discussion with your engineer though as this modification is technically not compliant to the National Code of Practice which requires that “the wheel track of passenger cars (or derivatives) must not be increased by more than 25mm beyond the maximum specified by the vehicle manufacturer for the particular model. This means that the rim offset must not be changed by more than 12.5mm.”. You would be moving from a 6mm positive HR rim to a 26mm positive Commodore rim i.e. a change of 20mm, more than the 12.5mm allowable. Queenslands Code of Practice may allow it (not sure – haven’t dug through it in detail:
http://www.tmr.qld.gov.au/~/media/b3ea8 ... ctions.pdf).
c) run HQ front and Commodore back. No need to offset drill, but a lot harder to find a matching set of wheels.

If it was mine and I was chasing cost, I'd have the 26P discussion with the engineer first. If they will allow it, run Commodore front and rear (option b).

If they won't allow it, go option a) or c). If asthetics are a worry, find the wheels you love at a price you can live with first, then choose one of them.
Cheers,
Harv.
327 Chev EK wagon, original EK ute for Number 1 Daughter, an FB sedan meth monster project and a BB/MD grey motored FED.