Migrating from 10.4.11 Server to Mavericks (App) Server

Hello All!

We have recently purchased a new Mac Mini 2.3GHz quad-core i7 with OS Server, in the hope of replacing our current G5 X-Serve running 10.4.11.

I would like it to be known that I am not a server administrative wizard, but am aware that the migration from 10.4.11 to an Intel-based system is not as pleasant as I had imagined.

Our G5 hosts our Mail database (Cyrus IMAP) - and this is my primary concern. I have read that the new Mail service differs hugely from Cryus (Dovecot - if Im not mistaken?). We rely hugely on archive mail for legal reasons and losing it is not an option. I will of course have Carbon Copy Cloned the X Serve before carrying out any migration, and certainly intend to leave the old hog alone if I need to revert to it at a later stage.

The only documentation I can find is the Apple Technical document which outlines how to migrate from 10.4.11 to Snow Leopard Server 10.6 - this is an issue for me, since I have Mavericks now installed on the Mac Mini and "reverting" back to an older OS is rather difficult (especially with no superdrive).

Could anybody please point me in the right direction? Is it likely that I will need to downgrade the Mini's OS first? Or have Apple already produced literature which can guide me through this process?

Help!