To be a bit more helpful, it seems that making unique arms just to fit a set of wheels would be impratical. Such a venture would have pretty limited applications, catering to a very small segment of hobbyists, thus making it less profitable or practical. It is much more practical to do what is currently being done, which is either creating late model wheel copies with correct backspacing (as several aftermarket wheel manufacturers do) or more commonly, purchase correct wheel spacers to correct for the large backspacing of stock late model wheels. This is much less expensive and much more practical than creating unique suspension arms.
Hope this helps.