The only place where you can buy it is
http://www.easyzapper.comIt took me only 3 days to get mine shipped to Ireland by FedEx.
I made it work with all my devices, including some typical european models from Nokia, Wharfedale, GoldStar, ... (don't have a Sky Digibox to tell you)
When it's not in their database, the remote can learn it (digitizing) . When it can't learn the IR signal (rare), you can always grab the code from another Remote Control model (i.e. Pronto). On top of that, you can count on the technical support, they reply and work fast!
Last thing: of course don't expect the ZAP feature to work in Europe, the appropriate service doens't exist for us (yet?) but you can easily remap this button.
Cheers,
Daniel