I had a set of banded GP steels on my last van in 8.5 front & 9.5 rear. Tyres were 225/55 17 Kuhmo. No spacers used.
The van was lowered by about 70mm.
I ran around on this setup for about 8 years with no rubbing issues and it was a nice comfy ride.
Hope that helps in some way.
I can dig out some close up pictures of fitement if that would help as well.
Also, if you want more reference for size variations, there's this thread on the T4 forum that dates back to 2012 when GPs were pretty much the only option available. Some of the attached pics to posts are no longer visible anymore though.
www.vwt4forum.co.uk