You would have an easier time buying the right alloys instead of trying to get a plate made up to support the differing stud patterns?
I have a 12mm aluminium plate on my Audi to fit my larger PCD Lambo wheels which would be a pain any time I got a flat tyre as I'd need to then take off the plate to fit the spare wheel. I'd suggest keep looking for the correct PCD and Offset.
Pepper