Hi Seb and Jens,
What rights do you need : normal user ?
Basically I just need g++ and the build-depends of cgal, no special privileges. The box should run testing or unstable (or chroot).
I've a C7500 you could use.
I don't have a clue what C7500 or 712/80 means ;-) The faster the better. A total disk size of 2GB (Jens) might be too small, but I will try if there is no other way.