How about this - can you SSH into your CentOS server (which has no GUI) from another Linux machine that does have a GUI? If so, then make sure the virt-viewer package is installed on your CentOS server then try the following. I just tried this on a Fedora 10 server with no GUI (just the core OS plus the required KVM packages and dependencies) and it worked for me:
1. Log into a Gnome desktop on my Linux workstation
2. SSH to my Fedora 10 server, being sure to enable X11 forwarding ( e.g., ssh -Y <SERVER_IPADDRESS> )
3. start the virt-install command like so:
-c /data/iso/Fedora-10-i386-DVD.iso \
-f /data/F10-virt-OS \
After a bunch of output is spewed to the terminal, a graphical window pops up which has the Fedora install running in it.
If you do not have the ability to SSH into your server from another Linux workstation, let us know and we'll keep digging...