I guess you'd have to install/update programs via rpm's / from source and compile new kernels by hand if you can't connect to the service.
To get the specific files you could use aptget or a similar service - google is also nice
You are still able to follow the errata releases via redhats site so you can focus your search for specific files from there.
If you are starting from scratch on a new machine why not venture into Debian or Gentoo - that way you would probably have access to security updates etc. as soon as they generally are produced/become available and at the same time you would have access to cutting edge software technology