To do an FAA check is no problem since the JAA checkman is also an FAA examener so he can do both checks in one simsesion. however the JAA program is approved via the UK-CAA and in the netherlands there was a big problem to get the typerating in the licence since the dutch CAA didn't aprove the CAA JAA aproval.
So before you go be sure the German CAA aproves this program
SOAB