Wow, thanks people, I'm glad I resurrected this thread.
Pilot Warehouse sent the 2003 charts, saying they'd exchange them for 2004 if they got those in time. They arrived today, and I've been happily route planning when I should be working. I fancied Freidrichshavn or Konstanz...preferably the latter as we like small airfields. Then I looked on here...so good to know it's recommended. English speaking is not a requirement as my co-pilot is fairly fluent in French and German...but it's nice if I can understand things too.
Westy, I'll look up Egelsbach on the chart, and pm you if it looks like we might stop there. Could always do that one on the way back, perhaps.
What else...we're taking lots of cash so will be OK for fuel at smaller airfields. What about oil? Is that usually available if needed?
I'll update this before we leave, if not before, and look forward to comparing notes with PhilD when we get back.
Thanks again to you all.