I prefer "ereader", short for "electronic reader". It's the obvious and most correct choice. Also, it has a direct translation to the portuguese nomenclature: "leitor electrónico". Although we don't say "eLeitor" or "LeitorE".
The import of the french word is completely efemerous, it's just adding another name to the currently used, complicating everything.
So I decide: from now on, "ereader" is the official word!