Welcome on board, Robert! With our increasing German readership it makes me think of adding a German-only section for those who are interested in e-books but not comfortable with the English language.
Your project sounds very ambitious! If you can keep us updated, we'd be more than happy!
Just be careful in regard to Mobipocket: I remember when ubook added support for .mobi books, at least one person from Mobipocket, who frequently visits this forum, wasn't very amused.