Dual upgrade - version and OS

Hi, Our master server is currently running NBU 7.0.1 on RHEL 4. My goal is to upgrade NBU to 7.5. The compatibility list says that NBU 7.5 is not supported on RHEL4, so I'll need to upgrade the OS first.

I'm going to build a new server with RHEL 5 and take the IP address of the old server. My questions are about the migration. Do I have to install 7.0.1 on the new server, or can I go right to 7.5? If so, how do I migrate over the catalog? Seems standard stuff, but it's the 1st time I've dealt with it.

Thanks, Mike