I'll send you the data, but just creating a proof-of-concept with one string translated by gettext (PHP on Apache) would already be a big help.
IIRC, it was a bit problematic to change the language on run-time, but it's probably possible.
On a side note: I've decided to create a live-demo + repository for the new look for aMule.org. This way everybody interested has less problems contributing and testing of new features is easier.
I guess SVN is the way to go, although I'm increasingly fond of mercurial (and use it for private projects) and have heard mainly good things about git.