Mailing the story:
Stella takes CentOS (which takes RHEL) and adds many of the desktop packages you're missing; along with RPMForge/RepoForge, you're pretty much all the way there
It's nice to say that the very-very-very-long-term-support releases in the Linux world that won't cost you arms and legs -- the RHEL-source-fed CentOS and Scientific Linux -- are there if you want to run the same distribution for years and years. But that's only true if you can stick with the relatively anemic selection of desktop packages available in the CentOS, Scientific Linux and, by extension, Red Hat repositories.