CentOS 6.3. Update from mininstall to full edition
Solution 1:
Yes.
Once you get an installed instance, you should be able to yum install or yum groupinstall the packages or groups you want to use; as they should come directly from the yum mirrors on the internet.
This is more or less how I do standard installs -- I do a minimal install, then a yum -y update, then install the groups and packages I need. Since the updated packages are coming from the internet anyways, there's little point in installing packages from local storage that are going to get immediately updated.