Well, no need to worry, the font files worked after patching the CSS just a bit.
Here is the promised package, and I can guarantee that it works : I tried it myself...
I think the Droid Serif font looks nice, but is a bit densely packed for my taste. I'll try and use the Droid Sans just in case it's more spaced. In the meantime, I'll stick to Caecilia.
Cheers, and thanks for the help !