Hmm. With EPEL plus RPMForge you should be able to get most of what you want in a way that passes Centos QA but this one seems missing yes. You can get Lua from the "kbs-CentOS-Testing" section of the http://centos.karan.org
repo. Since he's one of the Centos maintainers that hopefully should say something about trustworthiness but still notice the package is in the testing section so YMMV(VM).