The issue with that is the lack of a right control key, as the OP mentioned.
I'm also a long time emacs user (about 12 years now), and I find that the UNIX layout is the best, which is what the HHKB has, as well as most Sun keyboards. You can also purchase that layout from Unicomp, if you so desire.
If I were you, I would look into an older keyboard that is still only a 101 key. I'm making an assumption here, but given that you said you're a long time emacs user, I assume that also means you aren't using windows (windows versions of emacs are pretty atrocious), so the lack of windows and menu keys wouldn't be much of an issue.
I'm not sure if there are any new Cherry MX based 101 keys, but I know you can still order them in buckling springs from Unicomp. Alternatively, look for vintage boards on ebay or here in the classifieds. You said you were in Germany, maybe contact Ascaii and see if he has any 101 keys left.
As much as I love my HHKB and my UNIX layout IBMs, I know that layout isn't for everyone. The IBMs at least have large control keys on the bottom row (if you use them for that), and you could easily map the HHKBs outside keys to control as well, if you desired, using xmodmap.