Here's an interesting link on Amen-Ra including something about the etymology (or history) of the name. This god was the "hidden one".
Here's a link on the Biblical Amen. Here a second one: Amen: that more or less agrees with the first. The word means "it is settled", "truly", or "verily".
These seem to be two different words which just so happen to be spelled the same (in English).