If you mean the graphic novel collections of the El-Hazard Manga, the
Viz Store still sells 'em, and if they do then other big online stores like
The Right Stuf and
Animenation undoubtedly sell them as well (and probably for less. I don't know if any of these places ship overseas, but I'd be surprised if none of them did.
If you're talking about individual issues of the manga... well, they might be tougher to find. Your best bet, I think, would be to try online comics and collectables stores, like
Mile High Comics. It's possible that you might simply be out of luck where the individual issues are concerned, though...
Good luck on replacing your collectables!