Went back and looked at the emails i had with a TTRS guy that did a conversion...

Looks like these guys in germany make a kit for everyones needs... although they don't have the wavy rears listed they have great prices and will probably send you the brackets only. even a 376mm rear conversion haha damn.. that'll look nice under the 19's!

Search C5 RS6 in the drop down to see all the products.

http://www.ultimot.de/?ShowForm=1&auswahl=Shop

Kinda digging those brake lines too....