"Sh" to "s" is simple enough. Sounds horrible to my ears, but maybe not to someone named Stavros ;). I've also been told that the double-p of Boppre looks alien in Greek.

And the "hu" syllable (like the sound an owl makes) was a genuine challenge. I think we went with χού. And now that my name is in the system, that's forever with this spelling, I guess.