RedHat AS is a commercial variant. You should have support from RedHat on it especially if it is a "special version". (Is this a PowerPC server? What makes it require a "special version"?)
RedHat Network is the support site for RedHat.
https://rhn.redhat.com/
Failing that you can always download the source for these packages and do the configure and make commands they require to build some specific to your server. I'd definitely explore the RedHat support angle first though.
Also you have verified the packages don't already exist with the rpm -qa command correct.
For exmaple: rpm -qa |grep compat-db
It may already be there but be a later version.
By the way - Oracle is really bad at telling you what you need based on what they had on their test server rather than based on what is truly required. (I've seen them give shared memory max guidelines that were larger than the total memory on a server because their test server was huge.) During the Oracle linking it will give warnings if it doesn't find exact version but if you have a later version it almost always is backwardly compatible so will work despite the warnings. We see this often on our systems.