Uh... El Hazard is BIG. I have both anime series right now (downloaded them a few months ago.
As far as art goes, i really can tell if it's the same artist.
http://www.animenfo.com/animetitle,1...ard__the_.html
I'll look for the manga, however, all I have come across (so far) is hentai spinoffs. I think the series might have been an OAV.