Migration : Apache -> Nginx / courier -> Dovecot

Hi,
I would like to move ispconfig on an other server…
And for this, I've to reconfigure everything, and there is 2 change

The server is actually on Debian 6 and the new one will be on Debian 7 ;-)

1) I use courier and I saw that it's better to use dovecot, more easy and flexible to configure

2) Nginx take less resource than apache…

So I would like to have some advise and if it's possible to migrate from
apache to nginx / courier to dovecot.

Thx !

 

Up
Nobody have an idea for my migration ?