For us to give you accurate cabling info, will need either the model # of the TV or you will have to tell us what ports are available on the TV.
If you have the current Panasonic model that CC is selling it has no VGA port. While Panasonic makes some nice TV's, this is one of their drawbacks. They just do not put PC ports on most of their TV's.
Am not familiar with the G5, so I do not know what port it has.
If it has a VGA out, you are basically up the creek, because you will need either 1) a converter box (typically around $300) to use VGA to HDMI or 2) a converter box (typicaly around ($150) to use VGA to component. While I have/had several computers connected to HDTV's, I have never used one of these converter boxes, so I am not familiar with the issues that will result in trying to obtain the proper resolution on them.
If the G5 has a DVI port, then you will use a DVI to HDMI cable to connect them.