I would suggest looking up the organ score by Norris Stephens, published by Schirmer who are based in NY. ISBN 0-7935-5778-X
It is written on three staves and is in landscape format, which means less page turns. There are also some useful (suggested) registration and manual indications, and it also has the full vocal/solo parts written above.
The only down-side is that my score is in English, but they might do a one in German?
Best
Andy Scott