DFS Server 2003 R2 newbie

I am running server 2003 sp2 in a child domain. The powers that be in my
organization do not want me to run adprep.exe/forestprep and I need advice on
how to proceed. I have server 2003 r2 installed on two servers. The server at
our primary site is a cluster and our second site is a disaster recovery
site. I intend on setting all of our workstations to use the primary site
first and disaster recovery site last.

If the primary site goes down I would like the workstations to automatically
fail over to the back up site.

I want the files to be replicated automatically.
Is there anyway to achieve what I am trying to do with running adprep? If I
run add prep does that upgrade my dc to R2 and force the rest of our forest
to upgrade?


Many thanks