I think there are many other Eastern European names that wouldn't be taken so
in England.
I personally tried to name my DC's (with English names) so that it was not easy to make nasty playground rhymes from their names. Mostly because I had to put up with that the whole way through school.
Eustachy, I'm afraid, would end up being rhymed with moustachy in an awful lot of playgrounds.
And Eugeniuz would be seen as 'you genius' which would seem to be very pretentious. And what if they weren't a genius?
There is a boy in my DS2's class called Andrei. Nobody sees an issue with that. There is also a Tomaz.