I'm using DVI on my V+ box and it works very well.
You will need either a HDMI to DVI cable or a convertor.
You will also need a seperate cable for audio. Note DVI tv's will have a seperate 'HD' sound input on mine it was a 9mm socket which was quite hard to find. It's generally not the more obvious sound inputs
You will get ZERO help from Virgin regarding this through ,must support staff havent even heard of DVI (or HDMI for that matter)