I'm also using Opera 10.60 portable from Michalis (same link, stu90 posted) with luci-209. No problems so far.
~ Rolf
Edit: If you want a different language pack, look here.
Best place seems to be /Opera-10.60-6386-portable (or whatever your folder is named)/share/opera/locale/
Installing: Menu -> Settings -> Preferences -> General -> Language, Details.
Choose your downloaded file (xxx.lng) and that's it
