Kurt,
the boxerburners for the R1200S you can get from Roesner & Rose or from Rehcing (please mail Andreas Reh -
info@rehcing.com - and tell him that I gave you his contact details). Another source would be MKM Bikes (info@mkm-bikes.de).
This is what they look like
http://www.s-boxer.de/threads/27299-einbau-boxerburner/page4
Brgds
Oliver