Try a search at
http://search.rpmseek.com/search.html
That site has builds for various distros and versions and also has sources.
However RH8 is extemely old so you may have to build your own. You should at least be able to find the source at the above and it will let you know requirements.
After RH9 the product line diverged into Redhat Enterprise Level (RHEL) and Fedora Core (FC) with the former being the commrcially supported version. FC is the "free" one. FC6 was recently released so this means your RH8 is 8 versions out of date.
If you can do it I'd recommend upgrading at least to FC4 (or RHEL4) as that is the first one that has the 2.6 kernel which is what all current distros are using.
