[CentOS] How to? Set boot up display resolution

I have been given a replacement monitor for my CentOS-6.3 KVM test platform. It is an LG E2251 22in letterbox format screen whereas the unit it replaces was a 17" standard format display. The console messages now look as through they were output on Silly Putty.

The display itself displays a message to set the resolution to 1920 x 1080. I have found references to using the vga option in the grub.conf file. However, I can find no comprehensive list of what value to use. The references I have found actually say "see the source code in the Linux kernel tree", which does not strike me as particularly "user friendly" shall we say.

How do I do this or am I condemned to rubber band output.