Rather broad query.
You can but 22" rims on the car and still be legal...Can't remember the tyre size and rim width to do so...Rememeber putting a set on a VE when they were first released....So the memory is a little fuzzy over the exact details there....
Most people put the widest factory size on, which is 20" rims....To stay legal, you need 245/35 on the front and 275/30 on the rear....
For width, I think the fronts are 8" wide and fronts are 9" wide....Might be wrong there, but do a search on VE/VF HSV rims..They are what the common fitament is....