A revamp of server configuration

[j.vimal]

Hi
In our department, we have one NIS + NFS server which runs on Solaris. All the computers are clients, which get the required information from the server. We want to change the setup to the following:
A NFS + NIS server is going to be the new Master. For backup reasons, during failure, we would like to have a slave, which will be the old Solaris system.
I would like you guys to share your experience of setting them up. Or enlighten me of any better alternatives ...

Thanks!