If you don't need to record on the other box, your best bet would be a V HD Box, which just delivers the channels. Be aware, though, that there might be some limitation on where Virgin can install the second box in relation to where the main one is installed. When we upgraded to TiVo we wanted our old V+ box installed in a particular room, but we were told by the installation engineer that it wasn't possible, so we had to settle for another.
Going Multiroom with a VHD will add £6.50 a month to your bill, with an install charge of £50. The box can be either wired internally through the house, or preferrably if positioned near an outside wall, from outside.
Cable customer since 1993. Services: FH TV, Sky Sports & Movies (2xV+), Talk Unlim Telco, VIVID 100, Virgin PAYG Mobile