Its been a bit of a search, but thanks to a link provided kindly by Derek Ross the holy grail is within reach!
I heard back from the guy at AutoAlloyz.co.uk to and while the RS4 replica wheels are not, the Audi S-Line rims they have are single drilled, 5x112 ET-35 !!
and they look enough like RS4 rims to me!!
A Set of these, with 225-40-ZR18 Avon tyres comes in at £899 with free next day delivery and the usual fitting kit.