@thittato
incidentally i was just reading this blog post from Bill Harris. read them up and it might answer some of your questions:
Part 1: The Five Stages of Enlightenment…
http://www.centerpointe.com/blog/2008/05/19/the-five-stages-of-enlightenment/
Part 2: So, there you are, enlightened…
http://www.centerpointe.com/blog/2008/06/10/so-there-you-are-enlightened/
in the above post, Harris narrates the Five Ranks of Tozan.
i think a lot of people associates arahatship with only the Third Rank.
as CheleK said, there is a continuous process of integration which leads to the Fourth and Fifth ranks (and who knows where else).
i'm not (yet) an arahat but going to the Five Stages of Enlightenment sounds impressive to me

~C